Actually, I know a lot of people in the local science fiction community who sew or knit. And they're not even all costumers, though a large number are.
Baking and preserving is also not uncommon in fandom. Maybe we geeks are more prone to trying unusual hobbies?
Mr. Laser Beam wrote:
Take a look at the bottom right hand corner of page 2 of this PDF - you might see a name that belongs to, oh, me.
73rd Summer North American Bridge Championships daily newsletter, issue #7
There are plenty of clubs around, and tournaments pretty much every weekend. I doubt that newspapers would continue to run a daily column if it weren't reasonably popular - they could sell the space for advertising, after all. Also, the Toronto Star used to (I don't know if they still do) print a list of all the local tournament winners every week. It took up about half a page.
Now, sure, the average age of bridge players tends to skew to somewhere above 50, but every so often there's an influx of younger players. (I was part of one such influx in the early 90s, when I moved back to Toronto from university. I'd learned the game there, as it was impossible to walk into the lounge in the Math building and not find a game going on.)