Because I don't need to like you to debate you. This is just a plattform to debate shit. I'm perfectly fine to argue and talk with you about this kind of things, I just don't like you enough to care about what you want and believe when you can't back it up and it contradicts what I would consider reasonable or even desirable. Like, I've already told you that I would be fine with a Tinker class. I would prefer classes like Necromancer or Dark Ranger, but I would certainly try it out if it has an engaging playstyle. I am predominantly opposed to the concept of race restricting the class because it is neither necessary nor reasonable. Demon Hunters should be a one time thing and even then, I would be actually happier if they would open the class up for other races sometimes in the future (especially since my favorite set looks shit on female Blood Elves and I dislike playing male characters).
And I've already told you why I dislike you. You improved on some things, like being more open to alternative specs for Tinker like something artificer energy based, but at some points you remain obnoxious, like your insistance that Tinker has to be race restricted without any true or reasonable arguments. Opening the class to any race will hurt nobody. People like you, who already like Gnomes and Goblins but don't want to play them due to the lack of a fitting class to them have the option, people who not necessarily enjoy Gnomes and Goblins due to aesthetic reasons but enjoy either the style of the class or its gamestyle have other options.
And I would argue that the most likely way Mechs will work is exactly like a toggle button the same as the druid forms or shadow form. Likely giving an armor buff and possibly benefits fitting its tanking style, just as for example back in the Past Monks would gain stagger with the appropriate stance, but when you ask the game you more likely or not still remain the character inside the Mech, just as the Bear form of the Druid has only an aesthetic effect and nothing else.