I'm right there with you.
In fact, I'll state an even stronger position: I wish there were at least 3-5x more choices of platform for all form factors of computing device.
The duopoly that developed during the '90s was so clearly unhealthy, and yet it has set the expectations for OS competition so completely that many people seem to think it is an inevitability.
If we had a half-dozen or more mainstream OS choices, there would be massively more pressure for interoperability. That would mean that rather than lock-in, the various OS vendors would have to compete on things people actually like.
Now, just as you, I am a happy Apple user, and have been since before Jobs' return as iCEO. From where I sit, Apple does very much try to provide things that users want, to some extent...
...but if they had 4 more real competitors, there's much more chance that some of them would be providing many of those same things, and thus pushing Apple to do better and be better (just as you implied, indeed).