I signed up for this instance because:
- I align with its stated core interests (anti-capitalism, FOSS enthusiast, privacy enthusiast). Even if it wasn't the biggest or the flagship, it would be the most suitable in that sense.
- It's somewhat central, so when a new instance is added there's less chance I'll need a new account to post there
- It's not likely to fall. In my past fediverse usage, I have built up a history on a semi-random instance only for it to shut down without notice, while others became neglected by their hosts and stayed out of date. PeerTube didn't have account exporting settings so I lost what was there (luckily the raw videos were still on the hard drive).
- There's an implication that the devs will have no problem running the instance, at least on a technical level, and (this is my opinion, it's subjective, yes) they seemed reasonable when interacting with controversial communities like wolfballs.
However, as you can already see, I'm not limiting myself to posting on this instance. The Local/All filters in Communities do a nice job of making other instances conveniently accessible, but of course there aren't many that are popular enough to rank highly on that list, or have a unique topic that I have an interest in.