The idea that libertarianism in any way promotes life, liberty or property is frankly absurd and is why no one takes you (plural) seriously.
Any serious critique of the libertarian philosophy says that hard-core libertarians take those three nouns TOO seriously to the point that it infringes on those three nouns.
To play the devil's advocate to avoid getting to passionate:
Say, guns, according to some, take away more life/liberty than the liberty they grant. But to say that it doesn't "promote" it, even in that situation is ridic.