I think that I can list five main reasons to explain why good suggestions are so hard to follow (and it doesn’t matter if we are talking about the economy of a country or the settings of a GNU/Linux server).
- we are lazy
- we are unskilled
- we would like to make clear to everybody that the work of many people is useless
- we would like to stop someone from making easy money (someone that we support or whose support we need)
- we’ve built, through the years, a monster system that we don’t understand completely and we are very reluctant to change anything in it

Wow! They’re all applicable to my degree thesis :-p
See? They can be widely applied! :)