The processes are also designed such that people do not feel overstepped and ignored. After all, most things in life are about social status, or more immediately about salary status and job position.
If someone secretly implements an awesome feature, others might be envious as it does not seem deserved if their idea did not receive the same level of scrutiny by the usual processes as other decisions did.
Theoretically, it probably won't cause much chaos at all if programmers are allowed to add small GUI tweaks and the product likely benefits from it.
The degree to which this would work probably depends a lot on the extent to which the programmers have reached Kegan level 5, so practically it probably won't work all that well.