To be fair I understand where the threadstarter is coming from. In World of Warcraft the most hardcore players have the option to install addons to improve their gameplay - people that just play for fun DO NOT neccesarily have to have these addons.
My point being; if there would be addons like this for Diablo, only a selection of hardcore individuals would use them to kick their GR's up another notch. Those addons wouldn't be neccesary for casuals and therefore it won't make the game more difficult for them.
Right now the game is all about paragon and gear checks. It would - in my opinion - be nice to have more of a 'skill check' and I think something like a built in TurboHUD might add a little more skill to the game. Why? Well... You see the monsters on the map, a skilled player will know what he can skip and when he can continu more so than someone who does not see this. This way it is easier to dodge projectiles, something that requires skill, but the game normally doesn't highlight these projectiles very well.
Essentially I agree with the fact that some things in TurboHUD should have been integrated in this game a long time ago. Most specifically the locations of monsters and elites on the map and the highlighting of projectiles. For a good player the maphack isn't all that beneficial anyway. In many maps I know exactly what certain 'tiles' look like and I wouldn't even consider myself a good player. I'm more of a casual.