You seem not to grasp what a fact is, so there is no point in further conversation.I'm not sure what you mean, when you say that you "don't find them convincing."
You claim that Dragonsworn is not a class, that Dark Rangers are just Emo hunters and that the theme of the Necromancer is covered by Deathknights and Warlocks. I point out, how that is not the case, since unique classes has been thought up by the community. Your original statement is factually incorrect, since OP links to various concepts with a unique dragonsworn class, a Dark Ranger that's not just an "emo hunter" and a Necromancer class that is far beyond what we have seen with Deathknights and Warlocks.
That you don't like what you have read about said classes, is another but completely valid subject opinion.
We have some themes that covers multiple classes with different roles. Paladins and Priests comes to mind. One representation being the ranged holy user, the other being the melee holy user. We still need a ranged Death user, Melee Void, Melee Arcane user etc.
Sure tinkers are basically engineers AS A CLASS. Engineering is a few gimmicks that you can use, not anywhere near what a full class would be. I haven't seen the profession being a viable DPS, Tank or Healer