risk taking energy
There is a limited amount of energy in an organization. This energy allows people to take risks or not. If people don't feel that the risks they'll take will somehow increase their position, they don't take them. Instead there is an infinite amount of useless and harmless stuff that will fill the time and spend their energy.
There is this delusion that if the people are working, they are contributing. Contribution is mostly about taking risks.
Why should they take the risk? It's far better and rational for your employees to work on small and useless stuff than to try to take challenges to push the speed. Why should they bother to improve the performance of software while the most frequent thing you ask from them are related to the UI changes. The former has more risk to fail, and more difficult while the latter is easy and can be more rewarding.