There are a number of factors to consider. If a girl loves sucking cock, but is terrible at it, most guys would rather do anal with her. No teeth in the butt, lol. A good oral lover will try improving thier skills. It is far more difficult to be an expert at oral than it is anal. Buttsex and blowjobs both have the potential to be very messy. Even the professionals in porn can have accidents, (see porn bloopers).
Bottom line is this. Guys don't generally want to have a type of sex that their partner hates. It is much more rewarding to have sex when everyone is having fun and pleasure is going both directions.
Girl who loves to suck cock. My girlfriend is awesome at sucking cock...she gets so into it when she sucks mine, she has often had orgasms just from sucking me off.
Cocksucking is definitely the more important trait. Need to worship your bulls dick, suck his balls, and tongue his ass. That is the true sign of submission....once your bull starts fucking you, he will take the ass if he wants it.
It doesn't matter to me as long as she gives me a heads up so I can factor her interests into my activities. If she is so single minded that she cannot adapt to my interests I'm with the wrong gal.
Bottom line is this. Guys don't generally want to have a type of sex that their partner hates. It is much more rewarding to have sex when everyone is having fun and pleasure is going both directions.