This much is true. I'd say the best bet is to weigh the various factors based on how they appeal to you (you referring to a traveler in this case) and use that to decide.

For me, Delta is my only choice for non-stop service, and convenience is currently at the top of my list. So I stick with them, even when I'm dissatisfied with the level of service I feel they put out right now. If I was flying more routes where I'd have to connect anyway, I'd likely try the other options out to see which I liked better.

Comparing FF programs, while Delta seems to be continually stripping the things I liked about NWA's, it still seems better than most (or at least the same) from my view as a Silver. It's hard to compare since I've not had status on other airlines (had UAL, and AA at various points) in a few years, but from what I've seen of them, even the stripped Delta is about the same.