Why do people even keep bringing this up? Demon Hunter was a hero unit with easily definable abilities. Tinker doesn’t, at least not in any meaningful sense of the word. It had ONE ability that folks talk about and it is the Pocket Factory, an ability that’s not going to come to WoW in any other form than what we have already seen with Engineering.
Furthermore, Tinkers are in WoW already … and they are all Engineers, as Tinker is a specific title that some Engineers have. Demon Hunter is a definable class, Tinker isn’t.
Comparing the two is comparing apples to… not even oranges but the concept of the orange peel, since Tinker as a class concept doesn’t even have fully thought-out skin to brag about.