Why? There are many reasons:
1. Its well polished desktop environment
I returned using OpenSuSE from its 13.2. I'm a software developer and my daily work accompanied with numerous development tools and environments: python, C/C++/Cuda, Java, even PHP and Ruby. For me, personally, OpenSuSE + KDE is the most usable and productive environment for its comprehensive tools collection and usable environment. I have seen many people around complained about its substandard stability; but for me it's quite OK, experienced by hours of heavy development activities without disruption.
2. Its release schedule and rock-solid base
I couldn't say that I'm satisfied by the release schedule of the major distributions. Fedora release a new version every 6 months and life cycle is 13 months. Shorter life cycle means you have to upgrade your system more frequently. Not only that, every time it comes with several bugs at beginning. Fedora is the testbed for bleeding-edge techs and though it has more and more cool features, it's remarkably unstable and not suitable for my production environment.
What about Ubuntu? Ubuntu has the best support and stability for their LTS release; but it's 2-years release cycle. Sometimes I find some packages are outdated. But it's not the most important issues; actually I hate Unity, and I prefer .rpm system over .deb . I'm sorry for the irrelevant arguments.
What about OpenSuSE? The combination of SLES base with its enterprise-level stability and the novel features of upstream desktop components suite me the best. With 12-months cycle for minor release and 36 months cycle for major release, I don't need to do major upgrade too frequently while desktop applications are kept updated.
I know it's pretty stupid to say it but arguments are just arguments; sometimes you do something just because you feel like to do it. And yes I like the gecko, personally :)
It's pretty kool.
