They don't ACTIVELY submit because the phrase is offensive. It gives them power to choose, but then you take it away by telling them they have to choose to submit.
Actually, submission as a word, especially used in this context is a contradiction. It implies an act, like a choice. Choosing is contrary to submission. Submission the way you understand it involves a choice. Submissive people don't choose to submit. Truly submissive people RE-act. They don't act. They aren't PRO-active. They are RE-active. They aren't given charge. They don't make decisions. They go with the decisions that other people make.
Dominant people are PRO-active. They TAKE charge.
In general though, Women ARE more receptive than men are. Women are generally more go-with-the-flow types, just not in all areas. In many areas women are truly pro-active, especially today.
I would have to say that this is because women are becoming much much more independent because the men in their lives aren't stepping up and taking charge. You might have found that women don't take charge unless someone else doesn't do it, or if they do it badly. It seems to be a trend with the women in my life at least. With practice comes more confidence. So women are becoming VERY adept at taking charge.
That's why I try to take charge more often, especially with a receptive woman. I don't mean dominate. I don't make the decisions myself. I mean as the person in charge I am the coordinator between all interested parties. Everybody has their say and I organize it, and as the person who has taken charge, I get an extra vote if it comes down to a tie. LOL Just kidding. Truly wise people can tell when their decision is the wrong one for the group, and I do try to use wisdom.
Anyway, to answer your question, you are assuming that women have the power to CHOOSE to submit. You can't have power AND submit. There is actually no such power to choose to submit. Anyone that has a choice will almost always choose to dominate.
Some women do choose to change their ways though. If they have been particularly bossy and they see how their attitude is splitting up their marriage, they might tone it down a bit and let the husband win every once in awhile. But is she really submitting? No. She's picking her battles. She's still in charge. She gets to decide when to "submit" and when not to. That's not submitting, that's picking your battles.