You're right...maybe if the guys would be more vocal when jacking off like "this is for you fuckin bitch" or something...sorta like a bold comment to add to finish
I have been asking myself the same thing for a long time now. I think it might be true that (most) guys are just much more visual than (most) women. Every guy I asked about it basically told me it just looks crazy sexy to him. And that's supported by all the porn videos which prefer this "ending" because there is more to see. How do you show in a video that it feels much better to have your orgasm IN her mouth..?