Players do this. People. The forum faction war stuff is so deeply weird, I can’t wrap my head around it. Most people don’t even stick to a single faction.
Agreed that Silvermoon should be predominantly Horde, though. The faction divide as a concept has gone through some seriously awkward and contrived story beats to still be a thing, but it’s a core identity of the game that shouldn’t be tossed out like so much else that makes the playable races feel unique.