It is just as equally pleasurable, because a throat is as tight and narrow and as wet as a pussy, moreover throat sex or blowjobs involve a lot of tongue action which means that while a man is being sucked off, he is also being licked and seriously, what is more arousing than that? In fact, even in real life it is widely practiced by usual couples because it is more practical especially when the girl is on her week of the month or when you are growing tired of pussies.
Throat sex is a super popular and vastly consumed kind of porn.