It is certainly not crazy to think Taysom is better than Tanner (or will be next year). In fact, I think that is the more sane opinion.
It is not crazy to think that Tanner will be perfectly fine as a backup, learning and improving along the way. Many great QBs spent time as backups. Its great for the program to have some depth.
It's fine to think Taysom could get hurt again. Yup, he could. But so what? He can play (because he is better than Tanner) until he gets hurt, and then Tanner would be perfectly able to step in and play.
This isn't the cunundrum people seem to want to make it.