The most common problem apps for not backing up are games. I'm not a huge gamer, but losing my save progress can be pretty aggravating if there is a lot on there. Especially if you paid for it. That's why I don't buy most game's full versions. One factory reset and you more or less lost your money. I tend not to go back to them after losing my progress.
I'm not arguing the benefits of resetting after an update or that old data can cause problems. I'm just saying give us the *option* to make our own decisions. After the backup, restore each app and data one by one and make sure it's stable before going to the next one. Then you can take care of the problem maker if needed.