Yes, I have no idea why UI practices need to constantly "evolve". As far as I am concerned a lot of UI is getting worse over time so the less evolution the better.
There is some need to evolve as contexts change. Screen sizes and capabilities, computing speed, available bandwitdth etc.
Also humans seem to need fashion as a mechanism to show belonging and distinction. (Differentiate form parents generation, show affiliation to some sub culture, ...)
And then there is the hope to make the production more efficient. (Which may not work out)
