When he talks about the rejection of the permission culture I think Luis is correct, however surely this is a matter of education; clearly granting permission is explicitly what our licenses are designed to handle. The first of his suggestions, add an extra preamble to licenses, underscores that it's about education. And frankly I think the preambles we have are plenty long enough, and we generally go to a lot of trouble to educate about our licenses.
Perhaps he's correct that we should take care to orient license education more towards "people should be free to share & copy *without permission*", but I don't see this as a big difference to what we already say and do.
That said, I'm not sure that there is more unlicensed code around than there used to be, there's no evidence for that presented in the blog post. I suspect there has always been quite a significant amount, and the worrying centralisation of many people around github may have increased its findability.