The point is that none of the QB's on the board are "franchise QB's". And 22 teams passed on a "franchise QB" last year which sort of blows smoke over that argument.
I don't think the issue is quite that simple. Ratings for Quinn (last year) and Ryan range from top-10 "franchise" QB, to mid-late 1st round pick. Beck pretty much graded as a 2nd (to 3rd) round pick (and would again if he was coming out this year, IMO).
It really depends where people stand on these players. If people think Ryan/Quinn are really late 1st rounders (i.e. not a sure-fire franchise QB), then they would believe Ryan/Quinn would be only a minimal upgrade over Beck (and thus not worth considering).
However, there are plenty of people (fans, scouts, GM's) that feel that Ryan (like Quinn last year) IS a franchise QB. In that case, it would make sense to draft him, regardless of Beck. For example, if Parcells/Ireland are CONVINCED that Ryan is a franchise QB, I'm not sure I would want them to pass him up, just because we have Beck.
Absolutely, Beck's 4 games (or 3 5/8's games:)) are not enough to know what he will become (it would be better if he had not looked quite so bad, though).
Personally, I don't want to take Ryan. Beck has a nice arm, and I'd like to think we can develop him. I'd rather address other areas in the draft. I can understand the feeling, though, that we should take Ryan.