Lets not sugar coat anything here, Jake Locker hasn't been a huge success early, but as I listed in an earlier post he has actually been a lot better than most fans and the media have given him credit for in his short time in the league. So then the question is why does he need to have a big camp?
Firstly, Locker needs a big camp because he needs to become familiar with the new offense. This isn't going to be Chris Palmer's option route, pass heavy, stay in the pocket offense and hopefully he will see a lot more simple 1-2-run type situations. He needs to grow in this system and show his new OC that what he can't do and what he can do so that they can both have success.
Secondly, he needs to conquer the question that people have been asking all offseason: can Jake Locker be a franchise quarterback. The answer, of course, is yes. Locker has an NFL caliber arm and just needs to adjust his touch (or find a WR that can locate and run under his ball AKA Justin Hunter) on deeper passes. He needs to show the media, the fans, and most importantly his team that he is the leader long-term.
Finally, he needs to have a good camp so that he can build up a head of steam going against the Steelers. The Steelers are a weaker team than they were in years past, and the Titans actually beat them in their last meeting. If Tennessee could beat an established powerhouse in their stadium it would build confidence for both Jake Locker and the team. An aging defense shouldn't be able to hold up to the ground and pound style of offense the Titans should run and if Jake put up something like 20-27 for 220 yards, 2 pass TD, and a rushing TD that would do wonders for the whole team's mentality and it would reaffirm faith in coach Munch and the organization.