Well, on OS X, you'd better have a $99/year developer program account or you cannot sign software. For most users it's a hasse to either disable Gatekeeper or to discover Ctrl/right-click to circumvent it.

Of course, signing software is good. But I'd rather like to accept/verify a key on a vendor-basis and have that used to validate updates. E.g. APT with GPG signing does this pretty well and makes installing signed software via e.g. Ubuntu's PPAs pretty nice.

Linux (and FreeBSD possibly!) will never hit the desktop hard

I agree. And this is why it is important that organisations such as Mozilla and CyanogenMod exist and are well-funded. As long as they keep up with their counterparts, people and vendors will have a choice.

That's true for now, but the trend is clear - OS X doesn't want to open apps downloaded from the Internet without the binary being signed by a registered developer. You can work around that, but I had to Google it (and I was trying to install YourKit Profiler - an otherwise very legit app from a well known and respected company). Microsoft only allows apps installed from their store on Windows RT. We are not talking about Windows Phone btw - Windows RT is Windows for ARM devices. Windows 8 has the same policy as OS X, both moved to the app store model, both now give warnings when installing from third-party sources.

BTW, Android is allowing app installs from third party sources. It always did. Not sure how long will that last, but iOS and Windows Phone 7 are completely locked down in that regard.

It's about time we stop thinking of these companies as being our friends. They aren't. They are partners at most and the free market doesn't work well if customers aren't prepared to vote with their wallet.

Also, ChromeOS has a developer mode and you can always install a chroot Linux along side ChromeOS. In essence you can do pretty much everything if you are a programmer and you spend a few minutes searching online.

For the average user (read non programmer), less options is always better.