I fly a lot - in the last 18 months I've flown around 36 segments - half on DL - and half on AS - Delta is no more shitty with pricing than any other full-service carrier.
I flew DTW-BNA (then stayed for a week) BNA-DTW (then stopped for a night) DTW-YYZ (stayed for a week) YYZ-SLC-SEA for about 1200 bucks, for a first class ticket - this is quite reasonable when you consider the segments involved.
Consider that with DL/AS/AA/UA I'm going to pay about the same for a cross country ticket - within 30-40 bucks, even with WN or B6, you're still going to be paying within 100 bucks of the most expensive of the big four, and within 40 bucks of the cheapest on most routes - in general, its 350-500 dollars to fly cross country in the US.
... and yes, I'm perfectly happy to pay extra to have a for-sure, I know its going to be there, isle seat.
Incidentally, every airline charges a high premium for next day travel - even then on DL, I was able to go SEA-DTW-PIT for about 800 round trip, on a ticket booked less than four hours before the flight took off.