I fly between New York and Washington a lot -- averaging maybe once a week. I use the Delta Shuttle because my primary employer has a very good contract fare. Starting from that core of business, it is natural to concentrate my flying on Delta.
But Delta has been disappointing me lately. Not so much since 9/11, but earlier. So I reduced my flying on Delta (to 154,000 base miles last year!) and started flying more on United, which treats me better.
Anyway, it would be going too far to say that I "hate" Delta; I'm just disappointed in their recent direction. I still have hope that they will reverse course, but that may be wishful thinking.
Bruce