I actually don't think Hip is off the mark here. These coupy CUVs are utterly pointless in any rational standard anyway. So why not make it maximally irrational by removing the rear doors? After all, isn't the point about coupes based on sedans that the lack of practicality represents your status as a fun loving single person, open for business?
I don't mean to put down every sedan based coupes, as some do offer tangible benefits in weight saving and chassis rigidity, but you'd be surprised to know how few actually do. For example, the A5 isn't lighter than the A4, and the 3er coupe isn't lighter than the 3er sedan. My understanding is that one big opening isn't necessarily more rigid than having two smaller openings. So really, the point of most coupes are to reduce practicality to make it look sexier, and also to advertise the fact that the owner is someone who prefers to drive something sexy rather than something practical.
As for Hip sounding like a mad man as usual, I don't think it's because he wants something that isn't going to be very popular. I also don't think it's because he repeats that a lot. I think it's because he makes it sound like it's the most ridiculous thing in the world that the car companies are not making what he wants, as if that's a colossal business oversight. That's where he starts to sound crazy.