Earlier quoted context omitted.
You're asking a totally separate question - you're asking 'since tax payers funded the research shouldn't they be able to see the output?' That's a great question. But the question I was replying to was 'who is paying the reviewers'. The answer is that their employers are.
The question wasn't "who is paying them?", the question was "why aren't the publishers paying them?". And that is a crucial question, and not answered by the observation that they are already paid by others.
You 'pay' for reviews of your papers, by reviewing other people's papers.
All the publisher does is connect people up and produce the final product. You can argue that the cost to subscribe is therefore too high for that service. Fine, it may be so! But saying 'why don't they pay their reviewers' is to misunderstand what the entire setup is here.