As were homosexual acts not so very long ago.
Legalize one perversion, the rest follow as a matter of course.
Consent is actually a pretty weak basis for making pedophilia illegal. Pedophiles are already marshaling historical examples and modern studies (one coauthored by professors from Cornell and Georgetown) to refute the argument that children do not have sufficient self-awareness to truly consent to having sex with adults.
The nub of the problem is sex divorced from its purpose, which is the perpetuation of mankind. Homosexual acts, pedophilia, and bestiality are not suited to this purpose; sex is and can only be mere self-indulgence in these instances.
Polygamy presents a different set of problems.
"The nub of the problem is sex divorced from its purpose, which is the perpetuation of mankind."
So it is okay to have (heterosexual) sex with someone if they are capable of bearing a child (or fathering one)? Regardless of age? And as they are capable of procreation, it is not to be considered pedophilia?
So sex by an adult male with a nubile minor female is OK, because it has the potential to procreate is the malem in se? I don't think so. I think the issue of mature consent is where the rubber meets the road. The matter of procreation is a deflection from the matter of abuse, and sex without the potential of procreation need not be a matter of abuse. I think you have your moral boxes all mixed up. But then, I don't think sex is all about procreation. In fact, amazingly enough, humans are not really totally wired that way. The desire for sex is not limited to when the female is in "heat" in either gender.