For me, it depends on the girl. Some girls are just not very good at pleasing men. Maybe, she just isn't a good sexual pleaser and she needs to work on it some more. I can safely say that not every girl has been able to make me cum.
I will do my best to reply with an educated, humble and honest answer. Ultimately, it is up to you whether you want to listen to my advice or ignore it completely. Sometimes, my advice may be wrong; occasionally, it will be right. Regardless, I want to do my best to give people answers they are seeking.