My comments are littered with folks asking "why is it a problem if your blocklist is public on Bluesky?"
I'm glad you asked.
"Who you block" is a reasonable indicator of your personal alignments. If you block TERFs, you're likely trans-friendly, if not trans yourself. If you block white supremacists, you're likely in support of multiculturalism.
If you block government entities, well, you know how this goes.
Do I trust Bluesky to handle that information with care? Hell no.