How is this not a textbook loophole? I would like to be against getting charged sales tax for amazon, as I order a lot of things from amazon. But there is no good rationale for being against this tax that doesn't also apply to sales taxes more generally. If that's your position, that's fine, but I can't see the justification for handing amazon a tax advantage.
This reminds me of the (in my view quirky) libertarian position of being against gay marriage because the state should be out of marriage entirely. Okay maybe so ... but in the meantime we should have equality before the law.