It shouldn't be controversial that not sharing sensitive data with Facebook is "foundational to providing privacy" and therefore using a Facebook tracker to fuck users needs a solid, extraordinary justification like "valid" gun use by the police and military.
You seem to believe that this particular breach is accidental, but reckless incompetence on Backblaze's part isn't much better than deliberate disregard for user privacy: any online service from Facebook should raise a red flag.
If you agree that the sensitive part was in error, then you're just against sharing data with Facebook for ads? That's certainly not some unanimous global perspective as I'm sure you know, since that's their actual business used by millions of other companies.
You seem to believe that this particular breach is accidental, but reckless incompetence on Backblaze's part isn't much better than deliberate disregard for user privacy: any online service from Facebook should raise a red flag.