What? Nearly all of the articles here deal with libertarian issues. There are very few books for sale which are exclusively about value free economics.
Who claimed otherwise?
Not at all. It is a train of libertarian philosophy that embraces praxeology and the Austrian economic analysis. Economics is a study of action and incentives, which is crucial to any social philosophy. Whether another philosophy makes it explicit or not, there are economic premises implied by them.
Perhaps it isn’t as obvious with Objectivism, which I find very weak when it comes to economic understanding.
As an austro-libertarian, I apply my understanding to every facet of my life. The notion that it is only useful for economic matters (again, overlooking that economics is about human action) is a serious misunderstanding. Yes, we don’t talk about lifestyles, sex, culture etc here, but that doesn’t mean we don’t have opinions on it that are compatible with, and perhaps obvious due to, Austro-Libertarianism.