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.