Saying that the shells that buy their stones would otherwise be camping Ulli is fine. If they're not botting (hah) or pos hacking (hah) or a combination of the 2 (hah hah) then they don't overly concern me at Ulli. It's a huge spawn area, and quite frankly an awful lot of luck is involved in claiming him.
Which is, of course, why these groups would rather buy stones than camp them.
And Fire, I agree your choice to use the services of RMT is purely your own. The ramifications of that choice, however, affect the entire server. When someone buys Ulli stones, that encourages RMT to camp more Ullis, and given that RMT are a hell of a lot more likely to use hacks to claim... You get the idea. On certain items we don't have a huge choice, RMT dominate a few select drops and on the AH it's impossible to tell who is selling them to you. But buying bazaared pop sets is just low.
As for Guilt-by-Association, what's wrong with it? As I pointed out in Mattaru's ethics of botting thread, if I found out that my shell botted, I'd leave. As would a number of other people most likely. If you profit from someone else's crime, that makes you guilty by association. An accomplice to their crime, if you will. If your spouse brought home a car for you, and you knew it was stolen, when the cops came for them they'd pick you up too. Guilt-by-association only blows up in your face when you're a fucking hypocrite.