Don't assume so much then before judging how someone feels about a matter. It makes you look shallow.
I agree though, on Nazgrim seeming like a tool, i've even said it several times when people suggested he become warchief, he just seemed to much of a grunt character.
But that didn't mean I wanted to see him die, and having, as horde, to actually fight against him, feels like a betrayal from the developers pov.
Why they couldn't do something like they did in ICC gunship, have horde fight against Admiral Rogers, and alliance against Nazgrim.