The discussion has never been about whether a suitable back-up can be acquired. That is another fiction you invented. My position which can be easily quoted is:
Finally you are not the judge of what represents or does not represent a viable back-up QB.
A viable zone-read back-up could be any of the numerous draft prospects and current NFL back-ups mentioned in this thread. Just because you don't like them doesn't mean they wouldn't work anymore then your liking Cousin's ensures he'll become/remain a viable back-up.
---------- Post added January-8th-2013 at 09:50 PM ----------
In conclusion: Our current offense features and makes excellent use of zone-read to yield a highly productive offense. Becaue zone-read is a major part of the offense it only makes sense to have a zone-read capable back-up QB on the roster.