I think what Jim means (correct me if I'm wrong), is that it comes down to the difference between INTP and INTJ decision making process. INTJs are usually decisive when it comes to establishing a relationship (i.e. "do you want a relantionship? No? Fuck you then"). While INTPs like to poke around and meander, and thusly freak out when an INTJ gives them what could be construed as an ultimatum.