You act as if that's a good thing. Why shouldn't some, or even the majority, of these resources be used to strengthen the core game instead of more simplistic cash-grabs?
The thing you're failing to take into account is that, for the most part and certainly recently, cartel items are created for the cartel market by a dedicated team who makes things for it. The team is funded by sales of cartel market items. It's doubtful we would be getting as many new vanity items if they weren't being purchased with real money.