Things I love about Linux:
* if your hardware can do something, the OS will let you (try to) do it. No arbitrary controls.
* complete source code for (almost) everything you're running. If something breaks, you can read the source and try to figure out why, and maybe even fix it (and this is something I hate about proprietary binary-only drivers from e.g. Nvidia). If you want to validate what something does, you can do that too.
* modularity: Linux command line tools are like Lego pieces - designed to be combined to solve problems maybe no-one else has ever had. Windows PowerShell has learnt from this (and actually improves it somewhat, by adding an *object* pipeline). At your own risk, you may even decline to update certain components if they cause problems in your environment, and this will usually work out fine.
* installation and automatic updating of the vast majority of applications from standard repositories is easier than hunting down the right installer for an application and remembering to keep it up to date (or having yet another application-specific updater in your system tray or services).
* Linux is generally where leading FOSS applications show up first.
* strict separation between different layers is a positive for reliability, security and privacy.
* it runs on everything from a SOHO router to a supercomputer: no need to learn new tools just because the hardware is different. Applications can be recompiled for new architectures and run as before.
* generally, no jarring changes: typically, distributions evolve and usually with good reasons (rather than due to artificial trends, akin to fins on automobiles)
* designed to be debugged, measured and analysed to whatever degree you need.
* all development tools have zero cash outlay.
