There are some amazing male subs out there, but I have noticed that it has been hard for some submissive men, who really want to submit, to entirely let go of the cultural programming that tells men to be the most aggressive person in the room and to focus on what they want above everything else. For instance, I've seen a "submissive" guy in a club crawl on his knees after a girl, getting in her face when it was clear that she wasn't interested in dominating him. That kind of behavior can be frustrating for women who want to be in control.
I hope it doesn't sound like I'm being too harsh on men here. As a woman who has always been a "daddy's girl" and grew up wanting to be like her very proud father, it has been a real struggle for me to submit sometimes. I don't want to let go of my pride and my independence even when I know that that's what I need in order to be happy. I can only imagine what it's like for men who have a lifetime of being told that they have to be "tough" behind them.