It has always been acceptable, in the Windows world. Machines have always been seen as inevitably fragile and ethereal. This is why the likes of Dropbox took off, among other things.
Regardless of OS, if you don't have reliable backups then stuff like this will happen from software or hardware issues. Best to have automated system images nightly.
If you had installed btfs and something like this happend people would be all over the place, but on windows this is normal