Your customers hate your product because of the bad UI. The business is at extreme risk.
I work in a company that has products based on code that is twice so old as the one in TFA. The products started on HP-UX in '90-ties and was ported to run on current Windows. This brings a ton of legacy including things such as our own implementation of menus and buttons, arcane shortcuts and outright illogical and counter-intuitive behavior. I, as a developer, can't comprehend how this survives and I would love to bring in such progressive technologies such as context menu or a toolbar.
The problem is, that there is unbelievably huge inertia in the industry. We, the developers, are not the problem. We suggest a change and everybody, who talks to customer, from support, through training to sales screams: "you can't change this, the customers are used to this shitty way for decades and they would reject the change".