Why don't people patch Java?
Could it possibly be that some software which requires Java state that it doesn't work on the newest versions? We've got several packages that require different versions (e.g. Must be Java 7 but prior to u35). It causes a real pain especially when a user needs 2 separate versions installed.
Also I find JRE to be one of the worst updates to package up for rolling out via SCCM, as it does not remove old versions automatically, so can cause days of pain trying to ensure that an old version is removed before the new one goes on. You end up just saying, "sod it, they can keep whichever version was installed with their software as at least that works."
At least Adobe make it easy to roll out updates silently via SCCM. (despite all their other problems......)