To defend this implies that I would prefer Rettig over Laviano; not the case. But, whomever should start,if they are ineffective (as Laviano was at times last season), the other should be given a chance.
To your point, Rettig had ample time to seize the reins in practice and has not done so, but that argument cuts both ways. Laviano has all the snaps and game experience from last year, and yet has been unable to clearly grab hold of the QB competition.
Whoever plays, I hope they succeed, but if they don't, I pray we adjust and try the one with a somewhat different skill set. The idea that we had a QB that didn't find the end zone for 5 games (and again it could be ANY name) and opted to not give the backup experience was mind boggling. Any backup is an injury away from being the starter, it is my hope that a Coach would have found some game time to prepare his backup for that possibility. See, I want the TEAM to succeed whichever individual helps, I'm in. But, I really do believe that we will be employing both, since I just don't think either is "well suited" for the new offense.