Outside of a recently discovered (and Adobe-acknowledged) bug with focus-stacking, Photoshop CC 2014.1 works perfectly for me. And they have already stated they're working on this bug.
If you're having other problems the implication, since it works very well for a lot of us, is that you have a problem on your computer where it is not providing the Adobe software the functionality or resources it needs to work.
That you have had an older version work is of no consequence. It's entirely reasonable that newer versions of the software will require more advanced functionality of the graphics subsystems on your computer.
That you point out that other people are having problems is of no consequence. You're not the only person in the world with a computer that's not up to the task for whatever reason, and most people come to the forums to try to resolve problems.
While we all wish Adobe software would work in a bug-free fashion on every computer anyone decides to use it on, it's impossible to expect cutting-edge software that needs cutting-edge computing support to find that every user has a clean, well-configured, fully up to date and functional computer. You need to take some responsibility for the choices you've made in setting up your computer.
You'd be better off asking for specific help here on your particular problems than hoping for someone from Adobe to make a blanket statement that will help you in a court case. Helping users resolve problems is what we like to do here.
Imagine being asked, if you do take this to official channels, whether you have exhausted all avenues of making your computer work right in order to properly run the Adobe software. Might be embarrassing to learn that all you needed to do was change a configuration option or download a driver.
-Noel