Really? I just finished re-watching it and found the later seasons to be incredible. Better than the first two. Especially the climaxes of seasons 3, 4, 5. I definitely got more out of the second viewing, I had much more focus on character arcs than plot.
Different strokes, I suppose. There was a lot more black comedy near the beginning instead of just the grim realism of people making the same mistakes over and over again.