Well, the willingness to let someone sell your personal info certainly runs deep these days which is weird AF as far as I'm concerned but let's not forget, ZBD isn't a Nostr client, they're a games company offering certain social features...
My concern would be further down the line, when you've built a substantial following, made friends, built a reputation...then, let's assume that ZBD are actually good guys...but they get hacked and thousands of previously trusted nsecs are worthless...it doesn't even have to be them that are the bad actors...
But they'd be the ones to pay, via loss of reputation. It wouldn't take much, after a moment like that, for the people to fire up new accounts and reconnect with all the friends they've made here. It'd burn, but not as much as it would for the company. At least they're already here at that point.