Ok, so other question: what does "Set as default" option? Every project can choose other compiler, and it ignore default compiler.
For example: I want to compile "Release" version of codeblocks. So I have to add full optimization options to "GNU GCC Compier", because codeblocks projects use this compiler. After that I build my project in debug version, so I have to revert compiler settings to defaults.
In my opinion projects should be able to use currently set default compiler.