I disagree that the case-preserving fs is OS X's biggest weakness as a dev platform. I think its biggest weakness is that its library system is so convoluted and different from every other *nix platform. OS X has dylibs, Mach-O bundles, "frameworks" (doesn't mean what you think it means), along with the usual .a files and also a slightly different naming convention for libs. The whole thing is an ugly mess and is difficult to understand.