To be fair, one of the greatest "see the future" CEOs has said similar things. Just off the top of my head, I know that Steve Jobs said that no one would want a larger screen than the original iPhone had, and he said that 7" tablets didn't make any sense. Now Apple has a larger iPhone screen and 7" tablet.
That's not to say that Steve Jobs was wrong about the future, but he had to sell devices in the present which meant pretending that they were perfect even though they weren't. Ballmer may have been doing the same. It's likely that his failures occurred much earlier in the process, and then he had to try to sell doomed products which is where those silly statements come from.
It seems like they're moving towards it. They've been signing deals with cable companies and hiring people related to TV. It's certainly not an easy process, especially as people in TV are wary of Apple.
The Cocoa API is pretty well thought out, generally well-documented, and pretty well-engineered.
I agree, their APIs are generally very nice. But the last few releases of OS X haven't been great. Multi-monitor support will finally be fixed in 10.9, after having been broken in 10.7 and 10.8. Also, recent releases have become very slow. A 2009 Mac Mini running 10.8 is unbearably slow, while the same machine is on 10.6 is almost as fast as a recent machine machine with a SSD on 10.8.
Ever watch Steve Jobs promote Mac OS 8 or 9? Rumour is, he didn't use either (he used NextStep until Mac OS X). He also spoke negatively about video being on iPods while it was being developed.
Ultimately, you have to remember that he had an agenda, and if he wasn't selling it that day, then he would probably say something negative about the idea or implementation (of a competitor's product).
Yes, probably. But then again, Ballmer failed quite often. Also I wouldn't really think of any CEO bashing another companies product just for the sake of rivalry and then fail. Its a huge risk to take.
Also having to sell silly products again is the CEOs problem for having to decided to sell those. Its just that the past 10-13 years have been cluttered with bad products and I would assume the ceo had a major role to play in it.