It is an interesting argument and really comes down to the semantics of who owns what money at various times.
An AP makes the average RTP lower for others by picking off the +EV spots. However, it can be reasonably assumed losers will ultimately lose the money back anyway. The AP won money comes out of the pockets of the casino in the long-run but also out of the pockets of other players in the short-run. It is all perspective but the word vulture still cracks me up just because of the analogy. I don't think it is good to refer to the business in such a way as it is definitely negative.