Some subjects are so complicated that they really deserve threads of their own - public employee unions are a prime example. But yeah, I have some fundamental concerns about the concept. And it's an issue of increasing salience - we now live in a nation in which most union members work for the government, and in which they generally enjoy greater job security and richer benefits than the taxpayers who fund them. Whether or not it's wise, it doesn't strike me as sustainable.
Well on the first point, he is right - this is a big issue on its own. On the second point though I think his analysis demonstrates a lack of understanding about the rights of public employees. Public employees do enjoy greater job security than most private employees however that is not a function of public employee unions but rather a basic matter of due process under the United States Constitution. To boil it down its most simplest terms - public employees (for the most part) have a property interest in their job. The Federal government, via the 5th Amendment, and state and local governments, via the 14th Amendment, cannot deprive persons of their property without due process of law. And in the case of public employees the Supreme Court has held that due process requires pre-termination notice coupled with an opportunity to respond plus a post-termination appeal process.
If you think public employees enjoy too much job security don't blame the unions - blame the Constitution.