I agree with you in saying that this article is no argument against conservatives who only advocate that porn should become less accessible to children. In fact I'd say that any argument that is intended to target all conservatives is doomed to be overly generalised and easily rebutted. (Same goes for arguments intended to target all liberals.)

Nevertheless, conservative vs liberal cross-shouting looked fun enough that I had to poke it~

You've got a point in saying that paying the most for porn does not equate to looking at the most porn. And in any case, a general account of porn spending in a Republican state does not, on its own, implicate the conservatives that live in that state. I doubt there is any way of accurately figuring out how much porn conservatives look at, compared to how much liberals look at, short of committing unacceptable violations of privacy. Just asking the questions in a survey would hardly get you an honest answer, if indeed a number of people are hypocrites.

Though the following arguments might be made:

(1) If you're familiar enough with the internet that you're comfortable about giving out your credit card details on a porn site, you probably are familiar enough to have heard that there's plenty of free porn online.

(2) If you didn't realise that there's plenty of free porn to be found online, you probably wouldn't be arguing that they are too accessible to children. (How many children can pay for porn via credit card?)

I don't know what percentage of conservatives are against porn, and what percentage merely want to make it less accessible to children - and I couldn't find any reliable data online. But I was under the impression that most conservatives, and some liberals, were completely against porn, saying it encourages infidelity, degrades women, and provokes men into committing sex crimes - amongst other things. It's possible that my perception is skewed as the anti-porn crusaders are very vocal.