True that, Possession sucks because it is extremly complicated. Getting mad that somebody uses your hand is plain irrational, it is not like anybody is taking anything from you, you still get a normal turn afterwards. Possession could have been, "take an extra turn", but that's not particularly interactive and we don't want Dominion to be multiplayer solitaire, do we?
About Saboteur, it doesn't suck because some folks loathe de-Remodelling of their cards. That's their issue. The cards sucks because it is weak. I still use it though, as my gaming group considers the card to be fun in the Kingdoms in which it is not so weak. Yeah, weird world, they actually find Saboteur fun.
Ths is hardly surprising as fun is always pretty subjective. Alice loses the Knight split in a 2P game and doesn't find ththe constant hammering fun. Bob loses the Cultist race in a game without trashers and despite of the zillion Ruins in his deck he enjoys the game he loses. You play Dominion with a Eurogamer and he might mind all Attacks whereas the wargamers and Ameritrashers might love 'em. Who cares, you cannot satisfy everybody. If you mind devastating Attacks like Torturer or Cultist (I never use that overpowered monster myself but hey, as I said, Bob might find that card fun) you can simply play without them.
Back to Villain, it could easily end up being Raider-level weak which is why I find it a pity that Donald went for a simple (OK, that's the motto of the expansion) and weak Attack instead of a LFN's stronger and more complex one.
Just think about the repercussions, getting always hit by a 5er-Villain could e.g. make you want to green earlier to have a Province to discard. The card creates nice trade-offs for the active player and influences gameplay of the passive player.