I don't play the game, but most people who mock it are just grossly uninformed. Most of you wouldnt mock people who play poker. Now realize there are tournaments where it's not uncommon to take home 10k+ in cash.
I actually play magic the gathering. I play in tournaments against people of my own age with like interests. Its the same as having poker night with your buddies. There are quite a few people who were on the magic pro tour, who moved up to high stakes poker and do rather well. By the way, if you're doing well on the pro tour, you get free tournament entries, flights paid for etc. It's not uncommon to go to Japan, Germany, Hawaii etc in the same year for these tournaments. If you're good, you make a living at it, just like poker players do.
There will definately be nerdy dudes who play these games casually in the basement. But keep in mind there is a tournament scene. Where your average day people are competing. Just like poker, or tennis, or local basketball team.