FRED is a horrible, horrible beast, and it's very Windows specific. It could be ported with winelib, but that would be a considerable amount of work.
That's why we started wxFRED, which would be cross-platform from the get go, but so far very little work has been done on it. As I'm not a mission designer, and am constantly busy with other things, I have neither the time nor desire to really work on it. The same goes for most of the other devs (not having time, desire, or both). wxFRED is the only way that we'll get a native version of FRED though. For now, running it via Wine is the only real option.