So, it took him 5 weeks to get ready? Maybe so, but as long as they are benching Weeden now that's all that matters.
Putting the semantics of how long it'll be aside, yeah he didn't have the benefit of training camp so it takes a few weeks to get acclimated. In the meantime Weeden gets a few starts to prove himself. He didn't, and I think it ended up pretty much how they expected.
Remember, they kicked the tires on a couple backup QBs in the off-season, and when Romo went down, they immediately traded for Cassel. All of this suggests pretty strongly that they didn't really believe in Weeden.
Remember also that when they signed Weeden, Orton was supposed to be 2nd string. Orton's holdout forced Weeden into a bigger role than was originally intended.
Now, you could make the argument that if they didn't believe in Weeden they should have signed someone else this past off-season. And you'd be right, but that's a different discussion.