Inclusions should be based on "arguments _for_" not "there's no arguments _against_". User API is about value vs cost, and without arguing the value, there's no point arguing the cost.
I'm not talking about making the FD API private, I'm talking about FailureDetectorLoader, while there is value in letting advanced users be able to construct and plug in alternative implementations, I see no need for them to use their own loading of them from config, as that's already provided by the config setting for the default FD. Makes sense?