What's wrong with liberatianism?

I've included Mark Rosenfelder's Zompist.com on my blogroll from the beginning, even though his site isn't really a blog as such. I find him mostly well-written and thought provoking, and his politics balances all those ranting right-wingers on my blogroll.

He's written a long essay on what's wrong with libertarianism. You may or may not agree with what he says - I know there are a lot of libertarians on my blogroll, and some of them may even read this blog. Most of his points are well-argued and thought out, but he closes with the following comments:

Libertarianism is essentially the morality of a thug. It's a worship of the already successful, privileging money and property above everything else-- love, humanity, justice. And let's not forget that lurid fascination with firepower.

It's also the philosophy of a snotty teen, someone who's read too much Heinlein, absorbed the sordid notion that an intellectual elite should rule the subhuman masses, and convinced himself that reading a few bad novels qualifies him as a member of the elite.

Is he attacking a straw man here? It seems to me he's attacking the most extreme elements of liberatianism, such as the ranting wingnuts you meet on usenet, and using it to discredit the whole philosophy, in the same way that some conservatives use the worst excesses of Stalinism to discredit social democrats. Or is there a grain of truth in what he says?