Oh, petty reasons are fine. I can one-up you in pettiness!
The FIRE target for my desired life style is $11MM.
You know what, $30MM is better. At >$30MM you're officially an UHNWI. What good is that title? Well, I'm sick of internet strangers claiming "you'll never be successful if [something I like/do/have]". UHNWI seems a pretty universal standard for "being successful", so there's that. Getting there will show these people who I've never met and who don't care about me.
Am I gonna continue to $30MM after crossing my FIRE number? Maybe. It doesn't matter.
Your reasons aren't dark, imo. It's just a form of being private, being competitive, ... It doesn't bring any harm to the world, so why not?