The ability to change the perspective was taken out of the Options menu because it really shouldn't have been in there in the first place. As far as I know about perspective mode (which is very little), the way you map is completely different than for orthographic (the regular view) maps, so changing it will almost certainly make things look bad. The choice of view is also very much something the game maker should decide, not the player.
I've never looked at how perspective mode actually works, because I'm not interested in it. As far as I'm concerned, it's incomplete and buggy and not worth using, and I don't feel like trying to remove or improve it. I don't even know how to map with it.