You don’t need to choose a server with bsky, that’s it. It’s just one big blob of everyone where no one really cares what kind of content or how often you post.
With Mastodon, you need to pick a server, and then there’s funny things like “oh, you haven’t posted for a while, we’re blocking your account” or concerns that the server you chose may decide you’re not fitting. That and mastodon.social wasn’t available to register for a while as I recall.
Add to that the fact that your instance may not be federated with whoever you’re trying to share stuff to. Meanwhile with bsky it’s just “do you have bsky yes or no”.
People care about ease of use way more than whether it’s corporate or not.
I’ve had my accounts blocked like that a few times when Mastodon was relatively new. I guess it’s an instance-specific thing?
I don’t remember the exact instance any more, since I never went back there, but mastodon.social doesn’t seem to do that.