I recently played Dragon Age 2, it has auto-attack on PC. I got a bug in a dungeon where the auto-attack stopped working, let's just say the amount of time I had to manually click my mouse was ridiculous and pain inducing.

Auto-attack allows you to focus on other things and strategies. If the game was more action oriented with cool specialty moves like in AoC I could understand no auto-attack but that's not how this naturally wants to flow. Either make the game MORE action oriented or add in auto-attack.