Nobody said they would start? They are there if Taylor doesn't improve. Yates is a career backup, don't be surprised if he doesn't make the 53 and Cardale beats him out.
You will not win consistently in this league unless you have a great QB. Taylor could be that guy, you never know. We have to have other options.
Worse thing is Taylor doesn't improve, we pick 10 again next year, miss out on the Big 3. That will set us back another 5 years.