Linux zealots spend waaaay too much time on Linux...
"Don't need to, they all use the linux kernel, the rest is the UI. So you have to create one installer, let's say RPM and the rest, DEB for example take about 30 seconds to convert. Not a huge investment in time. "
Well, pal, it's not as easy as you think it is... It might be easy to convert a 5kB utility rpm to deb... but I don't think it will work that nice with a 4GB game.... I even think that it won't work at all. If so far, nobody's done it, it's beacause it's too much of a hassle to do :
- different packaging
- opengl dev is hard (not for you I know, but for real world programmer, directX way easier, and more productive)
- sound is a mess in Linux
- dependency hell accross distros : to install your game, you'll have to take in account, which version of which lib is used for that particular distro
- slightly different kernels (compile options+modules) which can cause great problems
Lusers been shouting victory recently as Steam decided to move from Windows 8... not because Linux is better, dear lol ! It's all because of the Windows store, that steam will eventually have to pay, and become a MS underdog like all those apple and android dev... that's all !

Also, you're talking about encrypting files and folders... Have you been further than the start menu ? Or have you ever used Windows xp PRO, PRO is important, because in PRO, you have EFS. In fact, efs been out since Win2k...

FOSS aren't compatible with business for one reason, which is written in the FOSS disclaimer : "NO WARRANTY, USE AT YOUR OWN RISK"

cron is an archaic tool, though it works well, you need to modernize a little more, get a ui... stop working with .conf text files ffs... Everything now is about productivity. Clean, brightly organised UI, make things productive. Text files don't.

Well about your 30% cut, Apple and Android all do the same, yet nobody's ever said a thing... But windows dev don't ridiculize or yell at people. If they were developping for Windows, Alan Cox, Con Kolivas, never would have leaved the boat. No the problem with Linux, is politics. Waaaay too much fragmentation, there will always be a n+1 implementation cause A's not happy with B's code cause it's not commented, yadda, yadda...

You got the picture.

edit@capeterson : you can actually set up something looking like an active directory with samba, acl, etc... but get lots of aspirin and a couple of whiskey bottle in preparation of the all-nighter you're gonna have configuring text files while cursing Linus Torvalds.