It covers her also - and that is important. It is why the law is written this way - the wording has been carefully chosen. If it only said that you couldn't have sex with your own daughter, we'd then be asking "why does the Bible not prohibit sex with stepdaughters? They're not blood relatives, so surely you can marry them? But might not that be abuse?" That would be a giant mess. So instead of only prohibiting a man from having sex with his own daughters, the Bible prohibits a man from having sex with any daughters of his wives - whether or not they are his.I always interpreted it as referring to a man with his stepdaughter..
This actually makes the Bible's prohibition broader so it offers more protection and covers all daughters in the household.
Those men are simply wrong. But more than that, they are evil - twisting scripture to support their sin. That's what Satan has always done - he selectively quotes scripture to justify sin. Check out how the devil tempted Jesus.And there are men saying that there is no incest between father and daughter because she is his property.