American Football: It's just a bunch of cavemen grunting at each other and chasing a ball around.
Knitting: Hey genius, why don't you go to Wal-Mart and buy a sweater for $5 instead of wasting weeks of your time knitting one? Weirdo.
Anime: Lame cartoons for kids and creepy guys who live in their parents' basements.
Baseball: A bunch of wanking off to spreadsheets and graphs while guys stand in a field adjusting themselves.
NASCAR: White trash watching other white trash drive in a circle.
Tabletop Roleplaying Games: Losers who pretend to be elves and knights because they can't get dates.
It doesn't matter how deep or rich a hobby is. No matter how many millions of people embrace it, build friendships around it and develop their own language and subculture to contain it, someone will come along and denounce the whole thing as a bunch of stupid nonsense without ever bothering to find out what the hobby is really about or why people love it. No matter how innocuous (or even healthy) the activity might be, you are never more than a Google search away from someone who hates the hobby and all who practice it with a reflexive and irrational passion. They have probably even invented a slur to describe those people.
The guy who watches five hours of television a day will look at the woman who plays five hours of videogames a day and conclude she's "addicted." Sometimes he'll even suggest that "something" needs to be done about all of these poor addicts.
This is because people are jerks. Nothing short of extinction will cure this.
A great illustration of the human jerk gland in action is the public attitude towards videogames. There is a tendency among people who have never brushed against a DualShock controller to dismiss games as "murder simulators" or to decry their mild flirtations with implied nudity as an orgy of grunting, sweaty, hardcore sex. This is another manifestation of this sort of innate species-level dipshit behavior. They see someone sitting in the dark looking at the blinking lights and never pause to wonder what the player might be getting out of it. Just like Rock & Roll was going to turn teenagers into degenerates and D&D was going to turn kids into Satan-worshipers, games are the Scary New Thing casting threatening shadows on the cave walls.
Most gameophobes would warm to the hobby if they just saw it in a form they recognized. The guy who used to meticulously build model trains or a ship in a bottle could be constructing an urban utopia in SimCity. Instead of watching revenge movies, he could play Max Payne. Instead of reading car magazines and wishing he could afford the exotic automobiles, the autophile could be playing Gran Turismo. Instead of gossiping at the PTA meeting, she could do it in World of Warcraft. Instead of seeking a cathartic release of tension and fear in Dawn of the Dead, she could play Silent Hill. Instead of tinkering with ham radio, he could try to figure out how to get Crysis to run.