[jetpm]

When I think about it, it feels like there is some sort of mental barrier that I have to overcome to make plans with strangers. Maybe when the meetups would be less personal like 20 random people going to a bar or club, I'd rather join in on something. Then nobody would realize if I leave, but if I bond with some people its fine.

[degenerate]

When you meet a stranger, the actual purpose of small talk is to try to find some common ground. Some people are better at it than others (I am horrible)... but if some common ground can be established, both people will have an easier time making conversation. That's why so many meetups are centered around an activity/topic. I would much rather attend a group of "20 random people that list kayaking as a sport they enjoy" than "20 random people".

[jetpm]

That's a good point, completely random would be too much, at least the age should be somewhat similar and maybe the place to meet is also a context, e.g. a bar already indicates a form of interest, different than meeting in the water park.