For most women, sucking dick is the appetizer to the main course. It is a means to an end...the end being fucking. This might not always be the case, but for most.
For me, sucking dick is the main course. It's as intense as I go sexually with guys. Unlike 99.99% of gay guys, I'm not comfortable with anal.
So...there could be some logic that I'm going to work harder at giving a blowjob than a woman who is looking forward to getting fucked. I'm going to draw it out a bit more, and enjoy it as the end-all, be-all sex act.
So in that sense, someone like me - might be in some cases - be a little more intense with dick sucking than a normal person who would just move on the the next course.