I don't know if you read the Article (lol), but let me quote it for you:
Groening and the show's executive producer, David X. Cohen, were happy that the demand was there, because they both felt they had more to say. "Not that I think our show is like Star Trek, but (the original) Star Trek didn't last that long, but it went on and on and on (after it was cancelled). And David Cohen and I talked about it; we had so many story ideas and so many characters that we hadn't gotten around to introducing yet. So I'm so pleased.
You could have said what you said after the first two seasons, but there are so many awesome episodes in season 3 and 4 it proves you wrong (The Sting, Jurassic Bark, The Luck of the Fryish, Godfellas..).
Futurama has gotten better and better.