He's just mad because he's been a little off his stride since that magnificent "Night Watch". I don't like his kidie fantasies (leave it to Rowling, or her superior, Diana Wynne Jones, and give us more Vimes, dude) and "Monstrous Regiment" just wasn't funny.
But. The first Discworld novel I located was on a display the night HP4 came out. I had the whole evening to read it, and I was hooked. The world's big enough for both of you, Mr. Pratchett.
Exactly - his comments are chiefly sour grapes.
Pratchett's a good authoir but needs to stop following the same format every book becasue he never abandons the same structure which means that even the most amusing characters can quickly become jaded.His best stuff is when he was fresh or when he switches genre and tests himself like GOod Omens with Neil Gaiman or Strata.