Males back then didn't fail to reproduce from the same social situations as today. They were not neets hiding in basements. Failure to reproduce basically means killed, exiled, or having your groups women taken (by force)
Yes, but they could fail to reproduce due to other situations. I think from this
> Failure to reproduce basically means killed, exiled, or having your groups women taken (by force)
Only "killed" supports the thesis that males were slaughtered