It isnt so much support of capitalism that keeps the "libertarians" (propertarians being a better description) or "New Right" popular, its a unsuffisticated I want to be a millionary mentality, there's nothing else to it, socialists have let themselves be portrayed as humble voluntary poverty sorts who bitch about the good life and no one in their right mind would find that attractive.
I mean I've spoke to people who have blown up at the prospect of owning mobile phones, personal organisers etc. because it's middle class etc. which flies in the face of trying to make these things available to everyone rather than a select few, which I thought was pretty socialist, maybe this particular example is a hangover from peoples disgust with Yuppidom in the eighties but it's an image the left would do well to shake.
Aside from that people who want to read very well written, almost poetic, accounts in politics, which isnt everyone, might discover the classical liberal accounts and through being impressed with this uncommon eridation etc. will think it can be made true or must be without thinking of the precapitalist context in which it was written, modern capitalism being essentially a betrayal of Smith, Mill etc. and that it was written by people trying to defend their monopoly and unfair advantages and freedoms.
Finally they, the supporters of capitalism sophisticated politicos or not, will blame someone else EG it's not capitalism it's statism, it's not capitalism its collectivism, it's not capitalism it's corporatism while refusing to acknowledge that:
A) these things are a result of greed
B) Greed is intrinsic to capitalism, something that actually see as good.