Here is why I think these kinds of dynamic pricing practices are bad: it may be perfectly fair and legal, but it forces a non-negligible number of humanity to waste time and/or energy to figure out if it's happening, how to work around it if it is, and just generally waste human potential on something that should be a simple commodity.
Same with points systems. Why am I forced to understand your made up currency and status system to get the full value of my money. There might be some benefits to price discrimination (which is in effect what a point systems achieves) but the collective time wasted dicking around with points isn’t worth it. Make all point systems illegal.
They do it by selling data, by points expiring, and by often only allowing points when seats would be empty otherwise.
And often retailers pay more at POS terminals!
This all ties into any rewards program. It's part of the package, even if points are granted for use.