(..crossing my fingers..)
The best reason to have a begining story, and explanation, is to give everything an explanation.
..fire and ice
..love and death
..kings and queens
..He-Man and She-Ra
..pigmen and snakemen
..scenery and star-alignment
The other way of doing it, that is neat enough, is the way they did the first episode, "the Diamond Ray".
They didnt give any explanation at all.
Because its a TV show, they just assumed the characters would slowly interact and something would come out of it.
So they just dropped Skeletor in there.
Is he after GreySkull or Eternia city?,, who knows?,, who needs to know?,, we'll just get the imagery out there.
Does He-Man live in GreySkull?,, why not?,, he could live anywhere right?,, maybe he used to live in the palace.
..and mind you I love the first episode.
The thing 'that is wrong' with telling a story is that it has a need for an ending or resolve.
So if you like shows like Star Trek, that never, ever, ever, ever end, then that may be what you get.