Concerning what's good or not, sexual pleasure has a lot to do with the psychology of the people involved. Fal, you say there's not much point in tongue-****ing .. But let's say that if you or someone else tongue ****s a girl while she's using a vibrator on her clit - if what you're doing turns her on bigtime, she might come from that even if she wouldn't orgasm on her own using only the vibrator.
Just saying acts can have a "turn on" factor that can give them value beyond mere physical stimuli point-scoring.
Of course, we know this. Just making a point.