I know this might sound petty, but the thing preventing me from signing up is your comfort level dispersing information through x.com. You said "meet.hn has a twitter page", but sadly, twitter is dead and has been replaced by something sinister. I can't support them, even tangentially.
The OP says in the signup that if you meet up in person and tweet a photo, he'll re-tweet you through the meet.hn x handle. Sounds benign, and it mostly is.
I'm just personally uncomfortable supporting an otherwise good cause wherein x.com gets more attention and data about the good folks on HN, because I really don't trust them and their data governance.
I don't think it's petty, goofy or unproductive to feel uneasy in a once-open place that put up walls, gates and signal-heavy signage.
But even before our present-day Compoundia, Twitter was losing it's way. Prioritizing engagement over users is a bad road.
Information should be accessible to anyone anywhere on any device, with or without an account. X doesn't fit that role.
Same reason I hate when companies have a Facebook page and nothing else.