Well let me ask you this question: "How important is it for a man to be strong and confident?". A man can be very nice and generous, but if he comes off as weak and insecure will other people, especially women, respect him?
The answer will be the same as the answer to your question.
Apparently it's extremely important. A while ago someone explained it to me like this; "Say you were the cutest, sexiest, most amazing wife-material woman on the planet. And the 15th most amazing wife-material woman was an extremely feminine nurse. That woman would get about four times the romantic attention that you would because of one simple reason: you are jet engine mechanic in the military, and she's an adorable scrub-wearing caregiver."
Women are feminine it's life and experiences with weak men that might change that on the surface, but every woman wants to remain feminine, but it's all there and comes out the second you see the right guy lol