It seems to now be considered acceptable to lock down personal computing devices as if they were game consoles.
I've got a Mac and an iPhone. I'll agree with you on the iPhone side. My iPhone is "locked down" in the sense that without rooting it, I can only install curated applications... although so far, I haven't found something I want to do that I can't.
But I disagree with you on the Mac. I've been using PCs since the early 90s. I use Linux (and occasionally Windows) at work. I bought my first Mac this year. In no way is it locked down any more or less than any of my Windows, Linux, or FreeBSD boxes. In fact, because I can very easily compile and install just about any *nix application on it, I feel like it's more open than my Windows box ever was.
It truly is great to have a fantastic GUI OS, while at the same time being able to drop to a terminal and use the standard suite of UNIX tools when I want.