Doesn't MS rely on users too? Users of Windows, instead of users of browsers, but it's still in both of their interests to get developers using their platforms.

At the end of the day, all large companies have to dip their toes in new technologies, or die. Some of these projects will work out and others won't. Small companies do the exact same thing, except instead of announcing they are discontinuing a project they go bust.

My approach is not to get too tied to any vendor's technology, because if you do, you're setting yourself up for a fall. The rise of open source and standards has made this much easier than it once was, luckily.