Keyboard shortcuts
The ability to customise keyboard shortcuts, despite what some of your staff seem to think, is an important accessibility feature.
I find what Adobe can do amazing, it's however very held back by its poor usability. Among the worst example is the fact that commonly used shortcuts, which have the same function for almost all other apps, for some reason have different functions in Acrobat. The number of times that an incorrect shortcut has interrupted the flow of work (because, of course, I can't find the well-hidden tool that will fix the problem I'd just inadvertently created) means that quite often, I use Adobe only to import a document to Word where I can complete my editing in a more functional environment. Given shortcuts are such a base feature, the reason why many people aren't complaining may be because they just switch to different software.