Okay, so I pipe in...knowing full well the danger to my own life. LOL.
This is an experiential not a factual account of my dancing experience.
I had four flipping lousy, sucky terrible pros. In the middle of that I still advanced and made progress because it mattered to me, and I snuck in coachings with a great female dancer who reworked some of my bad habits. I was very concerned because the pro I was affiliated with after my first year was a trainer for studios in the area and so I ended up driving wherever he was teaching that day. SADLY the teachers at this chain thought I was a pro coming in to coach them. This did not increase my confidence about who the chain had hired for dancers.
I left mid-contract because I wasn't happy for a number of reasons, including the fact that I wasn't making progress.
I moved to an Independent after a ton of research and found my current pro. He has several women who are mediocre and they are dancing with him because they like to dance. I have no problem with that. When I started dancing with him I was the WORST person in the studio. I had no idea where to place my feet, I had bad everything, and my dancing was absolutely sloppy. After 8 months of drilling and feet that range from bruised to bloody after a lesson and more homework after that I would say I'm a good dancer. He refuses to lead something I can't do myself. If I can't keep my own balance or perform a skill we drill until it's in place.
He doesn't just use the mirrors, he KNOWS when my knee has flexed, when I'm on the wrong foot, when I haven't got my toes turned out and he's brutal. I have also under his training become a very good dancer, with sharp crisp turns, good lines, and a solid understanding of my steps and his steps. I put in a solid 3-5 hours of practice for every lesson I take with him, by myself because he has trained me to be able to perform without someone's steadying hand. If I don't practice, he knows and do you think he's pleasant about it?
Can a pro teach an amateur? Yes. Do most of them bother? Absolutely not.
To be honest under the pressure my pro puts on me, most women would quit. So its a matter of how many women who are doing pro/am really want the bother of learning and how many just want the company?