There is a difference between liberal and libertarian. Libertarianism has a fairly narrow support even in the US. Those who argue for less regulation also want to ban abortion. The most libertarian representation in US politics was Greenspan and he seemed to walk back on it in 2008. It's a niche point of view in the United states.
Moreover, if libertarianism has value, it should be defensible without appeal to the support or lack of support in popular culture.
I'm not talking about libertarianism in the context of American politics. Liberal and libertarian have similar (or even the same) meaning in political philosophy. The basic idea is that they view freedom as non interference.
I'm aware that most places in the world are not liberal. Fine with me. There's no need for every country or culture to share the same values. But in countries where libertarian freedom is a value, e.g. the US and UK, it should be defended.