It seems that a lot of players liked playing origin characters in DoS2, especially in MP.
But from what I heard it's not because players wanted to play an origin pre-made character : it's because custom were less interresting (no specific quest, no specific reactions to events,...)
Yea, it's a bit misleading to say people loved the origin system when it's obvious that the origin characters are so much more interesting than any character that can be made by the player. It's like giving someone the choice between a day old hotdog and a freshly cooked steak and saying "90% of people enjoy steak therefore we're only going to serve steak from now on".
Isn't that how it usually goes? A player made character should have their backstory left up to the player, rather than invented. Even in stories where the character has certain things decided for them (like you are Nerevar), the players past is left mostly ambiguous.
Games with pre made protagonists allow for more elaborate back stories for their MC. Then you have games like KOTOR that mix the two styles, but in those cases the writers had a specific vision in mind for the PC.