Why do all that work all over again if you're going to get the same game, though? C is not a deprecated language or anything like that. UQM will still be compilable for the foreseeable future, and the source code is available under the GNU GPL. There is no reason whatsoever to not use it.
I would understand if you were talking about making an entirely new game similar to Star Control II but different, but that's not what we're talking about here.
C isn't deprecated, the way you access the graphics card, physics programming, 3d programming, sound design etc etc etc is. It doesn't bring me anything to work on that code except making UQM HD (not to mention it's not fun for me to do so), after that I can't use the experience to make other games. THat's the thing.
But if you want to do it go ahead