You’re right, a lot of factors contributed to that. And then TBC saw the swing to the otherside. A pretty race on Horde that could be a Paladin was all it took to salvage that factions playerbase.
The problem is that drip never stopped, and as expansions went on more and more things contributed to that drip and it’s still not stopping to this day.
I don’t like how Horde players celebrate the death of the opposite faction for some BS forum RP. It’s a serious issue to the game that needs to be addressed.