Well, if they weren't so keen on making the Horde the villians, it could have been OK.
I mean, they basically followed their usual plot. The evil side make a dramatic strike (kill Varian, Burn Teldrasil) and then the plucky heroes rally and win in the end. Except, of course, they were using a player faction, so they couldn't go as far as total Alliance victory. So they pissed off both sides. The Horde is sick and tired of the villian bat and the Alliance couldn't get their victory over evil.
A truly nuanced and grey faction are could have been interesting. Of course that would have involved an original plot, rather than a retread of Garrosh 2.0.