It depends on what the goals are. I don't think "something different" is a valid goal. There should be a shortcoming in the current choices, and a way to fix the shortcomings that can't be done with the current choices. Too many proprietary(defined as particular to an O/S, not license) choices reduces interoperability between systems, and locks users into a certain system they may have trouble breaking out of.
The 80s were the bad old days of computing, where there were a ton of different takes on the computer and O/S, with none of them able to talk to each other. For all the bitching people do about MS, they helped push PC technology by standardizing things around the IBM platform. Linux probably wouldn't be where it is without MS. It would be a hobbyist O/S people tinkered with in their living room, or confined to the server.
Point? Choice is good as long as there isn't too much choice. Also, the choices should be distinct from one another, and not just do the same thing differently. Something like Time Machine could be done within an existing distribution, or if there were no takers, it could be done as an offshoot distro. Creative thinking isn't confined only to the new. All it takes is someone to say "You what would be cool?", and running with it.
I don't think Linux is going anywhere any time soon. If there were questionable bits inside, they could be fairly easily changed. With it being open, I'd think the patent trolls would have already tried going after them.