I think respecing would maybe break multiclassing a bit.
As you could level up as a single class then respec over to a multiclass for more abilities.
It would feel a little weird or at least I think so.
This is a game where you kinda have an idea of what you want to do with your characters before you even start.
Then I would at least like to be able to see what my character will be able to get in my level up's in the creation screen.