Well, it appears it's working against you, so why would they stop? Against an aggressive player, they are afraid to reraise, because they don't want the aggressive player to go over the top. However, since you are playing passively, it appears to them that they can get you off of your hands, which apparently they can. So even if they're weak, if they're beating you for any reason other than pure luck, they're outplaying you. It doesn't matter if they're a complete donk who raises every hand he gets. He's finding a way to take your money and it isn't by getting lucky, which, like it or not, makes them a pretty good player.
Think about what they're doing though. It should be pretty easy to beat this person. Fold when you don't have much, even if you sense weakness, and then just trap when you get a hand. If they're going to keep betting with marginal hands, and especially if they're going to reraise you when you raise, then you should be able to get so much out of good hands. I would love it if someone raised every time, because the second I made a good hand, I would just take all their money.