I agree with you in wanting some of these as default.
I believe the default setting are those that minimize the need for more computation and thus provide better performance.
Remember that there are those that are starting out with no prior experience, so the 1st hour of using the software is critical... if there are extra icons and colors and such that the new user did not specify it my lead to confusion and in some minuscule amount it may degrade system performance.???
just trying to see it from a "global" perspective. but I agree that the advanced user would like these things to remain set.
Ideally this is not a matter of default setting but rather a tool that stores ALL setting during upgrade, crashes, MP, or just to share with a colleague.