This might be why people don't want SMNs much. (Coil Related)

[Huntington]

Ninja Looting is always annoying, but not live devestating, ...

but i don´t see how this is SMN or Coil ... or even ARR related.

It was something that annoyed me for a few minutes, nothing after that.

Reasons I see stated when looking for PF groups on why they don't want SMNs is usually one of these few reasons:
1. People don't control or use their pets effectively
2. They do not keep up with Black Mages in damage, or in particular fights, they want more Melee classes to take advantage of a fight's mechanic(like the snake's Tail Whip attack which they like to activate so he doesn't do any other attacks for a few seconds, which any class could easily run over and trigger while attacking, but since a Caster would need to be moving and not using all of their spells, they don't want anyone else besides a Melee because they can lock-on and swivel around the target)

There have been other reasons like Bards over SMNs but right now I'm not coming up with anything more concrete.