Several reasons, actually.
The first is that, as of January 15th, I have been unemployed, so any loose cash that I have been able to scoop up has been going to pay bills, etc.
The second is that, to be perfectly honest, I'm not comfortable at tickle-related gatherings. I've been to five (one in Columbus a few years back-where Bella injured me LOL, two of the recent Michigan parties, and the NWOT in Lima, OH last summer, and the recent Cleveland munch). Although the vast majority of people I have met are first rate, I just feel like a bit of a wallflower.
I've made a few new friends, and one or two who have become very important parts of me, but discussing it in an open party-type forum just isn't my gig. I think of myself of as a pretty outgoing guy who has a decent gift of gab, but when it comes to discussing tickling, my gears grind to a stop, and I clam up immediately.
Another reason is that I just would never be caught dead going to an "adult" or "dungeon" type club. As those who I have chatted with probably know, I'm not into bondage or torture tickling in the least.
About 10 yrs ago, I was very close to a friend who was not only into tickling, but into...heavier...things as well. She invited me to go to a club in Miami with her "Master" (a term which really chafes me as well, but that's for another discussion). I said to her "Sweetheart, you know me about as well as anyone on this planet. How do you think I'd react if I saw you chained to something and some asshole with a whip or something hitting you? I'd start busting heads."
My own beliefs are that tickling is just something that is best in a one-on-one situation. If I was to meet one of the ladies here, say in a bar, having a drink, I'd be a lot better, and more myself.
Perhaps someday, my views on gatherings will change, but for now, it is what it is.