Changes that are not done with ample notice of term changes that affect your prior transactions with the service provider are the "unethical" ones.

For example, having X miles in the "bank" and finding out that effective immediately, they are worth 50% of what they were yesterday. The argument that the program terms can be changed at will on their end doesn't cut it because they "sell" us through promotional materials award charts, earning opportunities, and so on. Announcing after the end of the earning period that the current period will have "reduced benefits" for your status - BAD - ie, the UA SWU situation.

Announcing changes that you don't need to participate in, such as from today forward, we charge for food, toilet paper, you will earn less for discounted fares, and so on, as you don't need to patronize that company anymore. I do restrict this comment to tickets you haven't yet purchased.

Every company has the right and necessity to increase prices, etc. from time to time. That said, a loyalty program based more on 'revenue' has a poorer argument in raising redemption values.