Firstly. If a trait exists then it must have an evolutionary reason. Not necessarily be useful presently but in it's evolutionary context.
For example diversity in sexuality, if at all genetically determined, must have a purpose.
I think that "gay" humans can be evolutionarily explained. It is an indicator of complex families.
Any trait that exists must have an evolutionary explanation.
I feel like steemit can be used as a sort of authenticator of authorship. Time stamp and stuff.