My own experience with Backblaze personal backup was negative because I had so many directories and files that it took them longer than they anticipated to prepare a recovery drive, but I know that I don't have a typical use case and I recommend it without reservation to people who want that kind of whole computer backup.
It seems to me that service that can't deal with the bug I'm actually having is awful, whether that bug is rare or common. As an individual user, I care about my experience, not the statistical aggregate of user experiences. (Generalised 'I' here—this is not my bug.)
Also, the official solution (checking all backed up files manually) is genuinely awful, even if this were actually a rare bug.
Ordering a drive from them is very expensive if you're not in the US like me.
There are some funny stories about Backblaze personally delivering an emergency drive to someone in a remote part of the world, but they don't help the median user.