I agree the rebates for a Diamond member were low, but last I checked 1% > 0%. Say you spend $25,000 with Hilton in a year, $250 is better than $0 last I checked. Not going to cry over it, but dislike seeing devaluations like this.
Hilton Amex card fee raises for no meaningful improvements (and losing Priority Pass is a big downside) is another example of a more significant recent devaluation. I'm a bit more upset about the Amex side of things. Raising the price on something, offering less, and marketing it as something better when you're getting less is a bit disappointing.. you'd think Hilton would have learned a bit from the Delta mishaps that isn't a way to treat loyal customers