I thought he was more a send-up of Ballmer than Gates, although that might just be the physical resemblance.
Ballmer himself probably doesn't like the caricature (he's a bit of an internet darling, isn't he? https://www.youtube.com/watch?v=I14b-C67EXY), but would someone who worked with Ballmer find it accurate? Likely.
Not to mention, Gates wrote the article about Silicon Valley linked in this thread.