The disadvantage of all *NIX systems is that there are many of them, and their syntax sometimes differs.
That is: "You can be a Linux guru in Ubuntu, but crap yourself in some kind of arch-linux"
What the hell the same commands can be executed in different versions of linux in different ways - a mystery, its mother, covered in darkness. More precisely, it is not clear what makes, for example, a bunch of different package installers do.
In fact, MAC OS is the most successful and unified *NIX system.
