> Same policy as with our runtime; in order to keep our own sanity, we will officially support Ubuntu Linux.
…
> Installer will (most likely – it’s one of the things we didn’t do yet) just be a .deb package.
I really wish folks would support Debian first, and let Ubuntu support flow from that.
The great thing about the Linux community is that it's full if crazy smart people who will go out of their way to make sure stuff is working on their distribution. And of course if something isn't working on your distro, it'll be just like the player -- send us a bug report or poke us on the forums, and we'll do what we can. But in order to not spread our resources too thin (especially considering that this is starting off as an experiment), we have to set some boundaries, and we need to do what will make sense for the largest number of users.
And case sensitivity problems will exist as long as we have a mixture of some platforms (Windows/OS X) using case-insensitive filesystems by default, and others (Linux) using case-sensitive filesystems by default.
While generally it's also true the other way around (if something is made for Ubuntu, it's likely it will work on Debian without big issues), it would be nice for companies to recognize Ubuntu's roots and make the support official.
Of course in practice the community will quickly report back to you something like "hey, change your dependency to include libjpeg-turbo8 or libturbojpeg0, in Debian there's no libjpeg-turbo8" (real example from early Steam package), however, maybe it's just me, but when I see something having official support for Ubuntu only it sounds like "we were too lazy to give it a try on other distros", while explicitly stating support for Debian-based distributions starts sounding much more professional :)
That said, the reason why they support Ubuntu is that it provides static targets. 12.04 will be supported until late 2017, which means that they users two years from now can install a .deb built today. Likewise, supporting 14.04 means .deb packages will work until late 2019. Especially for companies that want to develop on Linux, there's a huge benefit in first-party support from your vendor for the next four years.