If you don't have a franchise QB then it's probably better to have as many prospects on your roster as possible. Yates takes up one of those spots.
Yates woudn't take the job if that was the case because they would almost certainly not cut Taylor, their new high draft pick or Jones. That means Yates is a guaranteed cut at the end of camp. The camp arm is not going to be a QB as qualified as Yates, IMO.