Nothing like discovering your recently released app crashes on iOS 7 and being unable to download the SDK to find out why, or fix it.
Stories of unjustified bad reviews being left by users like these due to poor behavior on iOS 7 are really common in the community.
After all, they do warn you that you should never install a beta OS on your daily use device and they are for development purposes only.
At the same time, I do feel sorry for devs getting bad reviews because of compatibility issues. I haven't had any myself, but it's probably only a matter of time.
I know of some affluent high-schoolers who seem to consider it prestigious if you can show off a prerelease iOS on your phone.