But we celebrate a multiverse of possibilities and reimaginings in the comic world. They're explained but they are essentially just a rewrite, a different artist, a different vision.
I'm not sure where you draw the line. Some of my favourite LotR and Star Wars content wasn't what people would consider the main event, so if it meant not being able to have things like KotOR or various Middle Earth games, I'd rather we didn't draw a line at all.
I know, I'm focussing on the good, and there is some absolute trash out there... But I think both sides are important to consider before banning rewrites and spin-offs.