Lucasfilm or Lucas Licensing specifically came up with the system of tiers on canonicity not the fandom.
When Disney took over they made the claim that everything going forward would canon but they couldn’t keep things straight across their trilogy so no surprise they’re having some difficulties maintaining it across multiple medias. They don’t use the tier system anymore.
That’s how it used to be but it’s kinda hard to ignore the parts you don’t like when they’re in major mainstream films.
It is when the community devolved into “I like it so it’s canon” due to it. Honestly, just having the balls to admit that everything outside the movies weren’t canon seems to be too much for the fandom, than and now.
I don’t see how making tiers or layers of canon are bad.
Things like what were and have happened without out it anyway.
Sounds like it’s just another thing your going on about to bitch about how toxic the Star Wars Fandom and make yourself seem so much better than anyone else.
Considering how the #1 question with Vision is “is it canon,” I think the tier system did more harm than good. Honestly, just admit the Legends EU stuff was never canon and still love what you love without needing it to be canon to the movies.