Whether a member is using AI, or garbage posting is a matter of forum policies and has nothing to do with DT, and seeing JG misusing the trust feedback for many times without anyone doing anything about it, just shows how level headed his peers are for including him on their lists.
To be fair, he isn't the first or only DT member to have a bunch of controversy swirling around him--or even the
most controversy if I recall correctly.
OP, the trust system (as it has evolved over the span of bitcointalk's existence) is pretty damn broken IMO, and I've been saying that for years. In fact, I think it's broken for the main reason you mentioned, i.e., that anyone can leave any feedback for any member for any reason. That's just setting up a system of trust for failure, no? And if the default trust list isn't regulated properly, well....see how many threads there have been about JollyGood? A lot of his feedbacks are valid, but he's strayed off-course so many times that at this point he probably feels like his position on the list is secured for life.