it's pretty obvious what's going on here. Kirk watches them both practice and sees JVB is better then Rudock. The thing is Rudock could be really good and still not be better then practice JVB who has no pressure because JVB with no pressure is an really good QB. Problem is JVB with pressure is an extremely poor QB and seems to be getting worse.
The only way Rudock is worse then JVB in a game is if he has D1 talent and coincidentally preforms poorly under pressure too. Although that is possible, there is no reason to assume a QB that leads his high school team to a national championship can't handle pressure.
Kirk might be taking longer to realize this because he gets to watch them both practice and therefore is convinced of something that just isn't the case any more. Once you are convinced of something it takes a lot to make you think otherwise and that could very well be what the hold up is. He is holding on to the hope that JVB can play like he does in practice and if he does he will be the best QB on our team.