I agree that I don't understand all the DL hate when really all the FF programs have seen similar devaluations (not to the full extent, but certainly in the same ballpark). Honestly, as a DM, I fly to get places on-time, on the day that I planned. DL has been the best at this for my personal flying, and I think the data backs up that this is true in general as well.

While I can't say I am happy about the FF benefit changes over the past 3-4 years, I've always considered the benefits to be freebies and didn't factor it into the price of the ticket.

I can certainly understand that some would fly UA/AA because they care more about getting useful miles to get a free flight once or twice a year than they do about their actual weekly itineraries being executed as planned. But I wouldn't make that trade-off myself.