I think Shatel is simply writing about what many fans are thinking and saying. I've always leaned towards wanting to hear from a guy like Diaco because he makes ~$850,000 dollars to coach defense. IMO, that warrants a few post game remarks to the fans helping to keep you employed.
Plus, when Diaco or someone like him doesn't speak after that kind of performance, it creates a sort of vacuum to be filled by players, other coaches, fans, message boards, etc. I don't think that's a good situation to cultivate.