Earlier quoted context omitted.
people point to the rare bug report that deletes absolutely everything in the account. but at this point, I don't even know if it's true.
I've been hit by that bug, although it only deletes mail AFAIK. There's a separate bug that completely corrupts the mail database on compaction, making Thunderbird lock up including for every future launch. Its a beautiful open source effort but products that have bugs like that languish for 10-20 years just aren't reliable. I need my mail client to be reliable.
But we should not spread FUD. If you can link to the bug I'd be interested, otherwise it doesn't add much value to claim this.