I make no secret of my far-leftward (at least in the US) leanings, nor of my distaste for privileged assholes living in a thought experiment which, unleashed upon the world, would result in the deaths of millions, and corporate feudalism.
It is an immoral "philosophy" because their dogma, applied to the existing society, would result in "unintended" consequences, and for people whose battle cry is "laws have unintended consequences, therefore laws are stupid and should be abolished," the hypocrisy is, well, not charming or funny, just typically appalling. Allowing GM to fail, for example, wouldn't "punish" just GM's board for their bad decisions, but the thousands of workers who would lose their jobs at GM factories, those workers' families, the various store owners and employees in the town where the GM employees, now laid off and spending less money, live and shop, and even further reaching consequences, such as the suppliers of parts for the now-closed factory, their employees, their employees' families, and the various store owners and employees in the towns where GM's suppliers live and work.
Ignoring the real-world consequences because they're inconvenient for your theory is not only immoral, but monstrous and disgusting.
Their naïvete is inextricable from the enormous socioeconomic privilege that Libertarians have. They pulled themselves up by their own bootstraps, attached to the finest hand-tooled leather boots their parents' money could buy.
A common Libertarian argument is that if people don't like the conditions at job X, people can negotiate better conditions, or they can leave and find a new job. They also apply this to their perfect, free-market "minarchist" society, where each city/state/corporatofeudal region has its own system of laws and rights, so for example in Libertarian Utopia America, San Francisco would be able to have its own set of LGBT-friendly laws, while Alabama could have its own set of racist, homophobic laws, and the Holy Invisible Hand of the Perfect Free Market would sort everything out, because people who want gay-friendly places to live and work could move to SFO, and bigots could move to Alabama.
(Sorry, non-bigoted Alabamans. I know there are some out there. Just your state came to mind because of the Christofascism evinced by an elected official recently, in which he said that only Christians are his brothers.)
In a perfect world, where packing up and moving 2000+ miles is inexpensive and risk-free, SURE. But people aren't robots without ties to places, like friends or family. There are a lot of reasons that moving is difficult, like the cost of hauling all your things, or even some of your things, 2000+ miles, wondering whether you'll make friends there, giving up free or low-cost child care if you're leaving your family behind.
Only someone who's never had to worry about making this month's rent could so blithely say, "Well, you can just move."
Only someone who's never had to worry about being fired for missing work to take their sick kid to the doctor could so blithely say In the USA, we have the freedom to negotiate whatever vacation we want. The idea that it’s generous to force employers to give holidays is just populism for suckers. I get 5 weeks holiday per year, because the free market works just fine. Some people have other interests.
There are other reasons, like their privatization fetish and ludicrous belief that corporations are people, but other people have discussed those elsewhere.