It's home brew to begin with. Crit fails were never part of official rules. It wasn't until 5e (iirc, might have been a line in 3.x) that it was officially supported as a known table rule that was in line with official rules. That makes iconic a misnomer for sure.

Also, as this thread should tell you, beloved is not accurate across the board. I would even call it controversial to some degree. There are players and DMs that are emphatic about not playing with it in place.

Fun? It can be. But it is also very commonly abused and done FAR outside of the usual range of possibilities for a crit success.

Truth is, on a d20 system, it just happens way too often unless it's dealt with the same way as crits of any kind are. Same with a nat 20 for that matter, when it isn't an actual combat crit roll. You have to roll to confirm crits because they aren't supposed to be that common. Why should that not apply to other forms of the idea?