Totally agree. I've got a Macbook Air (OSX Mavericks) and a (Lenovo)Thinkpad (Arch Linux). I'd add to your points that it's not only a software issue, but also a hardware issue. Recently I've found myself tweaking the trackpoint settings and have gone so far as modifying the driver and the syndaemon utility just to be able to get a better user experience.
When it comes to Apple's hardware/software combination, I'm sometimes surprised by how Linux compares really poorly in my experience. Weight and form factor aside, the trackpad on my Thinkpad is awful. Really god damned awful. And I wouldn't usually complain much about that, but the other fact is that the TrackPoint nipple is probably equally as bad in build quality and when you move the pointer a bit, it seems to get stuck and continues to move your pointer until you rub that nipple left or right. The sensitivity of the TrackPad however, is a disgrace, and the minimum jump seems to be something like 10 pixels, on a 12.5" screen. That's very choppy.
So: when I'm on my Macbook, I miss the trackpoint. When I'm on my Lenovo, I miss the Mac's multitouch trackpad, and a better trackpoint.
Software will improve the experience, but better hardware has to come with that, in general. When it comes down to it, the best quality you'll get out of your money will probably come from a Macbook (throwing in the form factor if it's to your taste, which adds points), so developers end up going for the better hardware, the better user experience, and hey, it happens to come with OSX, which without much effort has this really usable development environment, unix utilities, etc. Good enough, I'd say, given what the alternative usually is. And I still develop on Linux most of the time.