Apple’s never ending attempts to stay incompatible with the computing world at large have caused many a problem with cross platform projects. Not every application you need runs on a Mac, a PC, Linux, or numerous other less common platforms. Being able to transfer your image source from one platform to another transparently can be critical.
The popularity of Prores has caused Windows users in particular many problems, as Apple refuses to allow native Prores encoding through Quicktime on Windows. Now there is now no need to avoid the general clunkyness, gamma issues, lack of metadata, etc, that Apple’s clinging to Mov wrappers introduces.