The biggest threat to Linux is a change in attitude. But in the end, getting the world involved has generally been a good thing for the Internet. The same for Linux. Without the popularity it might have survived like Minix survived, but it wouldn't be what it is now. It's hard to say what would have happened.
Money makes a lot of things possible.
It's probably a good thing in general as long as the attitude doesn't change. The people who are making the money are the ones that took the risks. They deserve the rewards. Linux can certainly compete with MS if it has good desktop applications. Much easier to maintain in a corporate world.