First, because the sneering tone of the attack on the popularity of the Tea Party movement is, to put it at its mildest, a nasty expression of the worst sort of pseudo-elitist snobbery current these days. It's pseudo-elitist because it exudes a sweaty yearning to be included in what the author so obviously thinks is a liberal bien pensant Club where you can stand around at gallery openings looking down at imaginary hordes of racist, bible-thumping soccer moms. And it's pseudo-elitist because its explicit notion of an elite -- ironically, its division of society into a nice, clean us vs. an unwashed them -- is not just blatantly self-congratulatory, it's antiquated (see research on education levels). The irony here runs deeper than the inability to see that the simplistic division into good guys and bad guys that he criticizes in the conservative right has more pertinence to his own rhetoric than to his targets'. It also applies to the attempt at intellectual substance that he borrows from Julian Sanchez, in invoking terms like "ressentiment" and "epistemic closure" to describe an actually quite vibrant, varied, and positive conservative movement -- this just misfires when aimed at the contemporary American right wing, but is not inaccurate as a description of an increasingly frustrated, angry, and confused American left.
Second, then, is because, despite my latte-sipping ways, and like steadily increasing numbers of people quite content to be non-elites, I'm finding that my reaction to precisely those features of the contemporary left -- of closed-mindedness and resentment as a character trait -- makes me want to give traditionally conservative themes another look. I'm an atheist, as I've said, but I've long since grown out of that adolescent need to display my superior rationality by disparaging other people's belief systems, and in fact I recognize that we all have and need such systems, whether they're traditionally religious or not. I think the notion of character, for example, is important. I don't look upon "family" or even "family values" as code, or merely as code, but rather as the names for something else of importance. Even, dare I say it, patriotism seems to me to be a good and indispensable thing in a world in which the nation is the only means by which a person's rights, freedoms, and most general values can be sustained. It's become customary, of course, for the left to sneer at all such virtues and themes in one context but then, when criticized, hurry to claim them back again, and take offense at the critics. It's what I mean by the frustration, anger, and confusion of the contemporary left, and it seems to me that Lindsey, in his demonization of the Tea Party right, either shares in that or is at least insufficiently aware of it.
So the third reason I'm not impressed with his recommendation that libertarians occupy a political "center" is because I think he's confused about the nature and possibilities of political space. Whatever we might think about the true dimensionality of that space, practical politics forces you into the linear range of alternatives that we've come to call left and right. Now, Lindsay, in his centrist recommendation, obviously doesn't dispute that. But he seems to think you can occupy the center just by somehow mixing together opposites like statist and anti-statist, Big Government and small government. You can't, of course, and the attempt just makes you look not just unserious, but silly, in a way that confirms all the geekish air-head stereotypes of the libertarian. Little wonder not just that "liberaltarian" went nowhere, but that parties named "Libertarian" everywhere tend to be relegated to the perpetual fringe of the political heap. No, if you take politics at all seriously, you often have to choose, who to ally with and, unfortunately, who to ally against. Here and now, the simple fact is that Big Government is a central element in the liberal-left agenda, as it's just not in the conservative-right. There are elements in either camp that anyone will find distasteful, to put it mildly (not the same elements for all, of course), but that's only the more reason why smaller government should be preferable to larger -- so that those elements have less ability to inflict their values on us all through state power.
Lindsey thinks, as he says, that libertarians are "tainted" by their association with conservatives -- I think, on the contrary, that the people who favor smaller government, regardless of the label they choose to pin on themselves, form a natural political alliance against those who wish, from a smorgasbord of agendas, to advance the intrusive power of the state. Such an alliance is good, not tainted -- and more than that, it actually carries with it some real hope.
UPDATE: I forgot to mention that Ilya Somin not only linked to this debate, but added an extensive and valuable comment of his own. Here's my comment on his, from the Volokh Conspiracy:
I largely agree with Ilya’s post on this, but also think a) it goes far too easy on the sneering Brink Lindsey (I like the comment from Serious above), and b) it relies too much on labels or pigeon-holes for very complex sets of political and personal values, beliefs, objectives, etc. — far easier to make needed alliances if we don’t worry so much about the label we paste on our foreheads.