Well for the most part I don't even really like maps that have buildings in them. I think those are "siege" maps to me, not battle maps. Battle maps are open field maps, that require use of terrain if you want to get any advantages over your enemy (and obviously teamwork/tactics/formations, etc).
Adding ladders is going to get archers off the ground and less vulnerable to me (lancer cav), so that's a negative for me, positive for them.
There's nothing that would benefit me from archers being able to go on rooftops, it would only hurt my chances to kill them. I still think it should be brought back because MOTF should (in theory) allow melee to win rounds if archers want to camp on a rooftop.