I just don't see how having 1's vs 1's in the Spring Game would do any good. The 1's go against the 1's during spring practice all the time, so having one more scrimmage with them going against each other wouldn't make that big of a difference. What it would do is set up lots of bitching by the fan base. Say Keller/Ganz/whoever really lights it up against our #1 defense. Then all anyone will talk about is how bad the defense is. Conversely if a QB struggles, all anyone will talk about is how they aren't ready and how the offense is going to struggle. Neither of these assesment would be fair from only watching one scrimmage, but you can bet your bottom dollar that lots of people would make those assumptions.
Having the 1's vs. 2's, etc may not make for the most excitment for the fans, but you can bet that those second string guys are going to play their asses off to show that they can perform. The past few years we haven't had the depth for the 2nd string to really give much of a challenge. but at most positions that is starting to change.
Everyone needs to remember that while it is a fun event and gives us a much needed "football fix" it is still a practice. Having one extra practice with 1's vs 1's isn't going to make a big difference in the grand scheme of things. What it does do is set up alot of unnecessary worrying and doubting that would come with good/bad performances on either side.