It's like telling me I have to drive a certain route to my workplace and I can't use any other streets other than specified.
No it isn't. It's like there only being one way to make the car go faster, and one way to slow it down. Of course, like all analogies, this is imperfect since one can use the engine to slow the car, or use the brake pedal, or even the handbrake.
OS X is full of complex features. Folder actions, automation, launchd for user and system daemons, usable system backup for everyone (no other OS has this out of the box), network locations (unlimited sets of network configurations for when you use your machine in different places that require different setups), custom scripting for applications, services, unix command line, timer coalescing for low power, mach microkernel. Not to mention higher level features like airplay, and the server package.
Which OS features are you referring to when you suggest they lack features that other OS's have?