"Purported"? The OP asked if it is "illegal" or "against airline rules" to sell miles. Clearly, it is "against airline rules" to sell miles, but the legalities are not so clear, and there is nothing "purported," that is a genuine legal issue. Differing opinions have been expressed in this regard, and those expressing them have made plausible arguments in support of the answers they have offered. I find such discussions informative, and I don't know why anyone who doesn't wouldn't simply skip that discussion if they don't. It isn't as though posters have taken the thread OT.

No need to. Two apparently native speakers of English just threw a few grammatical and orthographic punches in the course of their dispute over whether a state government could regulate FFPs. No reason for others to be concerned that they will be criticized for incorrect word choice or spelling.