I've encountered a lot of situations where so-called software designers ("so-called" because they are often graphic designers who ended up with the title "software designer" without the experience or education associated with that title) feel the need to make the UI look "better" when the underlying software doesn't completely work. This is like putting lipstick on a pig - it's still a pig.
Another aspect of this is that designers forget that users don't use their software as often as they might. They see things every day that they don't like, and they want to change these things, but the users don't see that problem.
One example of software that became less useful with changes is the Now Utilities suite for the Mac that was made unusable by constant changes. Useful features were removed or made useless. I finally had to freeze my environment so I could actually get my work done. This often meant living with other bugs because upgrading the software was detrimental to the system as a whole.