As you said, the rule could be configured in many different ways, which means that activating it by default would raise a lot of issues on the first analysis of many projects. So either we don’t activate these rules and hope that developers will do it manually, or we activate them and make SonarLint/SonarCloud/SonarQube more complex to configure.
I didnt say anything about defaults, the point you are making is going to be applicable to any rule. I dont see what that has to do with denying the request other than to prop up a straw man to give the denial more weight.
There is already an enum naming rule thats regex configurable (S2342), so clearly the ask is possible and probably has most (if not all) of the code needed available, and that one was not judged to make Sonar configuration overly burdensome. Why would you evaluate this request differently?
I’m asking for is a gap to be filled for C# rules (like it has been for Java.). Its a rather large gap because without it, the formats for other identifiers can be used in code and create confusion. I would do this myself, but SonarCloud does not allow for users to define rules.