Returning to the OP and the actual topic of this thread. Is it really the ENTPs abusing their "mentors"? Or is it the other way round?
I'm not sure if it's even a valid issue. When I was upset I perceived the situation as indirect abuse in the sense that I was adding stress to her already stressful life. That opening assessment quickly lead to more foreboding connections, which then morphed into massive pangs of guilt. I don't like burdening people that I care about (although it's really more that I dislike it when I try very hard to help someone and it ends up having the opposite effect) with issues that I consider to be problems that I should be able to handle on my pown. But again, because my report of the situation was based on a series of incorrect insights, I'm not sure if it's a common occurrence within interactions between most ENTPs-INFJs.
Other ENTPs and INFJs should probably weigh in with support or evidence before people begin thinking about possible theories behind the "mentor abuse" situation.