Dragons and talking dogs. That's all I have to say.
Technically, Barbas is a Daedra, and Dragons really aren't that Far Fetched. Most ancient Dragon Stories of Earth originate from the remains (Fossils) of the creatures we now call Dinosaurs. I don't know if you've ever seen a Dinosaur fossil before, but they look a lot like a Dragon to me.
And I think you underestimate how easy plate is to work in, if you are brought up almost from birth wearing the stuff. The myth of people having to be winched into their horse is that - a myth. The only time it applied was with late era (16th Century) jousting armour, which was not only VERY thick, but missing much of the usual articulation (so there were fewer weak spots for a lance to go through). There are reliable reports of people swimming across rivers wearing the full plate. And I mean swim, not wade. One Frenchman on a siege climbed to the top of a siege ladder in full plate by hanging from the underside of the ladder. The weight is evenly distributed, so the wearer can roll and get up fairly easily. Don't confuse battles like Agincourt or Crecy where the ground was very soft.
Oh, I know how people have a misconception that plate armor is like wearing a lead brick. The modern United States Marine carries about the same weight in gear on his back, as the average suit of plate armor weighed. The Marine is typicially burdened even more, because the weight is focused.
But it's still very possible to have your neck broken in plate. Specifically if you look at all of Skyrim's heavy armors, which don't offer any of the limitations to neck articulation that would stop it.
Not to mention, Hand to Hand fighting is still entirely possible in Skyrim. Argonians and Khajiits have very powerful Hand to Hand abilities, then there's the "Gloves of the Pugilist" enchantmet.
So really, your arguments are null and void, H2H exists in Skyrim, it's just poorly implemented.