I like to think of different web communities like these as different 'countries' with different cultures. Once you get over the initial phase of tailoring the websites to your liking, learning the etiquette, and just getting to know the place you become much more 'at home'. Sure, it's intimidating, but it would be to visit Poland as well. However, you don't get the niche communities that Reddit has on here. :/ It's just the way that Reddit was set up with the subs really facilitated a lot of small groups coming together.
I love polandball! I think reddit is still the best place for it though. With the way things are, Reddit is not good for a bunch of things it was at some point, but I think a site with reddit's design and reddit's massive userbase is still the best for polandball.