That ability should be gone b/c it was an awful and stupid ability and always used as a crutch by people who couldn't roleplay.
I agree that it should be gone, but can't get on board with the "cannot roleplay" comment.
I much preferred how Arcana Unearthed/Evolved handled Alignment. There was none.
It's highly fashionable to dispose of alignment, and good for an offshoot looking to distinguish itself from D&D, but ultimately constitutes shortsighted design for the main game IMO.
Alignment is one of D&D's features that people continually take for granted. If I tell you that an NPC is a CE 5th level wizard, there's one heck of a lot of information contained in a very small space there. I know that designers love to overthrow this sort of stuff because it seems so inflexible, quaint and archaic, but like a spokesperson for anarchy once said - it's not enough just to destroy things, you need to have something in their place.
You could put a paragraph of information on how to play a monster, but that's too wordy to describe in the manner I've done just there. It also cuts into a whole range of spells and magic items that revolve around the concepts of good and evil, disposing of a lot of fantasy flavour. And finally, once again, D&D is a game where Good and Evil are incarnate forces with gods and (fallen) angels at their disposal - this is not sim reality.
In the Monte game, orcs (if any) have a weakened archetype, because we don't know what disposition they are without reading some description....or at least can't sum it up in one word in the stat block which carries actual weight in the game: EVIL. Archetypal strength is a big plus for D&D, adding to it's mythological resonance and the ability for it's concepts to be picked up quickly by newcomers.
A random example of D&D without alignment is OD&D's Mandrake. It was listed as Chaotic, which is generally OD&D cipher for "evil", but that didn't seem to fit in this case. I remember trying to make sense of the description - do they mean this is a goodie or a baddie, or neither? This seemed an important puzzle when reading the monster (at the time), because it sorted out the intended benign critters from the antagonists. (Note that 4E goes further down this "here's how to use this monster" path. That's useful.)
AD&D didn't beat around the bush in this manner; it cut straight to the chase. (Incidentally I think the chaos/law axis is something of a white elephant and could be pruned without much impact, except on some D&D mythology about the rod of seven parts.)