Well, there were also "Left Behind" spin offs (a young adult novel series I believe) and a video game which was pretty terrible. That said, as someone who has actually read some of this it's not bad. People seem to mostly attack it just because it's "Christian" and heavily promoted that way.
To put things into context, most people on a site like this have probably dealt with things that have gone just as far without batting an eye because they didn't directly say "This is a Christian story". "Supernatural" is going into it's 10th season and has featured the biblical apocalypse, the devil, Michael the archangel and a whole cast of events and beings tying everything directly into Christianity as the dominant celestial truth. Other gods who have shown up have simply been powerful supernatural beings, most of them incredibly malevolent, at one point The Devil kills off a bunch of cannibalistic survivors of the Greek and Hindu pantheons (Kali was their leader).
Various anime and video games have also dealt with Christianity, and religious apocalypse in one form or another. Shin Megami Tensei has gone here, as has Neon Genesis Evangelion, and that's just the tip of the iceberg.
I've never seen why "Left Behind" gets so much flak, yes it sets it's own universal truth, since God is real, this means all other religious are false. This applies to any series that sets a certain "truth" behind everything, you can't play on the metaphysical playground and have conflicts that mean anything on a global scale while being politically correct and not putting in some way of saying all religions are equally valid to avoid offense.
At it's core it basically creates a global apocalypse, makes the anti-Christ the bad guy (it's not the first time), and sets up a bunch of good guys to fight him. It's not high art, but it's not terrible either, and I can see why it was really popular with a lot of people, and probably even has a following against non-Christians simply on the merits of the story, which I believe is being intentionally campy at times.
As the article points out "The Rapture" isn't something all Christians believe in anyway, but it does make for some interesting story material, and explaining a sudden, mass disappearance.
To put things perhaps into some context, since the books do question some of the fundamental concepts themselves, the basic reason why someone could be making a "god doesn't do this" argument is because in the story, he just suddenly causes people to vanish (all children go automatically). This means you have a massive apocalypse as planes crash when their pilots vanish, cars go out of control, fires start when the people tending devices vanish, etc... this crisis is what allows Carpathia who is in the UN to work towards seizing power. In the scope of Christianity it can be argued that free will means God can't sit there and punish everyone who does something wrong, otherwise nobody would ever do anything wrong, and he's be a tyrant, especially seeing as he's pretty much aware of everything. This means rapists and criminals, parents who smoke and do drugs and pass conditions on to their children, and everything else all happen as a result of free will. In comparison though if god say decides "today is the rapture" and takes the faithful to heaven to begin the end times, and as a result some driverless car goes out of control and pulverizes some poor atheist on the side of the road, taking away any chance of him ever being able to "see the truth" and repent before the end and still get into heaven, that's really kind of unfair, the guy didn't even have a chance to know something was happening to soak in the warning... and that raises conceptual problems. I could be wrong but the whole "the god momma told me about doesn't do this" thing could be in response to some event from the book of revelations (which is nasty) or just the initial wave of the rapture, where people are dying in droves without people even knowing it was because of sudden disappearances you know... good news, God just saved everyone at the church cookout, bad news the unattended grills have burned out of control leading to a massive fire, which is unusually terrible because a lot of the selfless firemen made the cut for being heroic and there weren't enough of them and other first responders left to respond in force to that and all the other problems....
I'm not a huge series fan (though unlike many I've read some of it), and the franchise getting a movie reboot doesn't excite me, but I can see why Nicholas Cage took the role. This is something with a decent, enduring, fan base that is likely to make some serious bank, especially with a real movie star at the helm and a decent budget. What's more Nicholas Cage is fundamentally playing "Redemptive Action Guy" which is a role we already know he can nail. One of the big questions about it's success is going to be whether it jumps from existing fans, to the mainstream, and that largely comes down to how they portray it. If they focus on the action and events, it might work, if they spend a lot of time on religious analysis, conversion, and repentant hand wringing, then probably not.
As a basic recommendation, I'll say that if you liked Steven King's "The Stand" (book or mini-series) on a lot of levels this is similar [Spoilers for old material ahead]. Albeit "The Stand" had a massive biological weapon outbreak acting as The Rapture (with the release caused by recurring Steven King all around bad guy, Flagg, who happens to be a demon). The Stand's basic set
up where you have a bunch of good people in the mountains, and a bunch of bad people lead by that demon in Vegas, and a war brewing as the forces in Vegas build an army to wipe out the other people and control the remnants of earth, is very similar to the relation between "Tribulation Force" and it's enemies. The big difference is that "Tribulation Force" can be fairly pro-active, where the point of "The Stand" the book took it's name from was sacrifice, where the people making "The Stand" travelled to Vegas, were captured, tormented, and basically never gave up their faith, despite never doing anything to resist which was one of the requirements (turn the other cheek) which in turn enabled god to intervene (with the ending, especially in the mini-series, being the defeated heroes 2" away from execution, the hand of god literally comes down and sets off a nuke... BOOM! good wins). This is a similar theme to his other works where god is defined as being unable to intervene without sacrifice (spelled out quite frankly in "Desperation" for one), and is the eventual "trump card" that comes up in the hands of a righteous man in stories like "Needful Things" (where the Sheriff's pretend magic tricks briefly become real magic when he enters into a final confrontation he otherwise can't win, having lost everything up until that point). Even "The Dark Tower" series which ties together a lot of his cosmology ends by sort of showing the surprise sacrifice (a huge one) that allows Roland to do what he does... in short King is a much better writer, but a lot of his stuff is pretty similar to "Left Behind" in theme, even if not as preachy (usually) if you can appreciate him, you probably will at least find "Left Behind" somewhat entertaining.... and as I started out saying, it comes out very similarly to "The Stand".