The two most important things missing from Linux are mass familiarity and certain important professional software suites. It isn't that Linux doesn't have software nearly-equivalent to things like the Adobe suite, MS Office, and AutoCAD. It is that it doesn't have those EXACT applications. Like it or not, in a professional setting, you usually have to use the big proprietary applications because that's what everyone else uses. Using standard software reduces compatibility and training headaches, and eases recruitment. Most technically-oriented professionals wouldn't even take a job that disallowed them from accessing and maintaining their competence with the standard software of their profession.