This is nothing to do with Joseph.  Joseph has very little say in the final roster.  It is all Elway.  Joseph is a rookie Head Coach (not like John Fox or Kubiak who came with some pedigree because of their prior head coaching resume) who is thankful to have a job.  He is no way going to stand up to Elway.  Elway had it for Sloter and did not want Sloter hanging around and making Lynch look terrible.