They still didn't explain any of it
Didn't even do a who's who
Sure they did. They show you the characters and what they do. Once you have the names and see them in any type of action, that's all to it to any of them.
You saw Prince Adam, and watched him turn into He-Man and Battlecat turn into Cringer. You saw Teela being playful with him, and be a good fighter in her own right. You saw Orko do magic, you saw the king and queen just be there. You saw Skeletor with some dumb ass plan, and Evil-lyn by his side doing magic. If any cartoon is full of one-dimensional characters, it's He-Man. There's nothing beyond surface level.
There never was really an explanation, they just sat you in the world. We never really knew why Skeletor wanted what he wanted...he was just bad.
Why couldn't they have just said it was Teela's show?
They could have gotten a better fan reaction without the bait and switch.
Teela's motivation comes of as selfish and nonsensical. No need to shyt on Adam and Man-at-Arm's to advance Teela.
It's not bad, but it's a different direction indeed. I have no problem with He-Man & Skeletor, but like you said, why not just say it's the Adventures of Teela. And since she was already a strong female character, so they really didn't have to do Duncan like that.