There is a Star Trek: TNG episode where LaForge gets stranded in a planet with a romulan, which says to him that should he have been born a romulan he would never be allowed to develop/grow up, due to having his genetic defect in his eyes.

The logic behind was very similar to yours. I found it cruel when I watched it, and I still do, but it's hard to deny the benefits to society.

Don't, worry, I've got you covered! And here, take one, too!

Lo Wang to a naked lady taking a bath: Do you want to wash Wang? Or do you want to watch Wang wash Wang?

Don't worry, I got this!

So Microsoft is not a Linux contributor but they have merely contributed code to the Linux kernel.

Right...

And enough to appear as one of the 20 biggest contributors.

Please, forget about this "oh, they MUST make Linux better on its own" mentality. As you said, Microsoft contributed to make it play nicer to their software... So what? Put yourself in their shoes: wouldn't you want your own software to be compatible?
Hell, if they contributed to fix the software controller in their espresso machines, it would still be valid.

Indeed, I agree completely with you. But not only the used, they also contributed back to the community. That alone sets them apart of the vast majority of the Linux users, at least symbolically.

Microsoft is one of the biggest Linux contributors http://www.infoworld.com/d/open-source-software/microsoft-counted-key-linux-contributor-now-anyway-190104. In my view they have absolutely all the right to use it, if it fits their solution.

You never watched Idiocracy, did you?

Read about it here: http://wiki.debian.org/Multiarch