Or it could be that it would kick in a duel just so they could impress Souji with winning!
But I'm definetely on the side of allowing the skills. The big difference between this and Grandia 1 magic is that Grandia 1 magic is storebought, and at least 3/4 of your party can equip all types of magic (Although there are at least some limitations if you factored in temp PCs that would make it seem more unique). Basically, you get a mana egg, and then you can equip it to whoever you want. While Auto-Endure may be gained the same way for each PC, it's gained in a fully separate manner (unlike G1, where you can choose). It's the storebought universalness that's generally the problem.
If the Auto-Endure skill was something far more extreme, it wouldn't change my view on it's legality, just on the game's rankability.
I don't think FE comparisons really fly here. I originally banned FE counters besides it was a facet of the battle system for both the ally and enemy side. Counters help and hurt you in a similar manner, so I was against them just helping you in the DL arena (Eventually changed it to characters can counter when they have range supremacy, so characters who are better at countering and avoiding enemy countering in game get a boost, while people who are stuck at one specific range will never counter. Which works awesomely since it can basically be applied to VH, ATL 2, Brig, what have you. There can be a few hiccups now and then, but it's fairly well balanced overall). Auto-Endure is only helpful, which puts it in a very different class to me.