Almost everything you commonly use on top of Linux is GNU, hence the term.
Most people and organizations tend to stick to Microsoft OS because of being constrained by 3rd parties, say, some Sysadmins prefer to code VBS and use their VMware vCenters on top of Microsoft. Which, by the way, uses a established hybrid kernel, theoretically a more advanced and safe architecture than monolithic, which is for instance Linux. Of course in practice something you can see in the Internet as the Linus Law applies, hence the classic OS flame and economic wars.
Well, on the other hand, many other people would install a Linux distribution in many scenarios, but a common use case is somewhat similar to that of Microsoft, for instance peoples could be involved in your project here, and even though some gurus (which use to prefer to develop from a POSIX environment) are maintaining the cross compilation to Microsoft, in the end you get the changes first and have better support if you use an environment similar to that of the developers, POSIX. That, and with this, the most part of the Linux OS' success, can be arguably applied to some GNU tools, such as coreutils (for instance your ls) and overall the GNU Compiler Compilation. That is the reason for the FSF and GNU people to insist in calling GNU/Linux that bunch of software packages that people will normally be using in their Ooboontoo OS.
I think Linus is fair pointing that Red Hat or SuSE would like to drop GNU from their products name, because IMO these are medium companies capable (if they want to) to drop GNU. That does not apply so much to Debian as it is a people's project, but he can have his opinion, as much as the GNU and FSF people in the other side and many Debian, Arch, Gentoo, Slackware... people in between.
Things have been like this for twenty years till today, but maybe this will eventually change. Some movements to be aware of: Arch Hurd, Minix (maybe at last is its time), Debian GNU/KFreeBSD, a potential Microsoft POSIX compliant OS, for name some.