Since the Seahawks are my favorite NFC team, I think I can shed some light on this subject:
Curry is more or less a player who was overdrafted. SEA would have traded down in 09, but since there was no rookie wage scale at the time (no team was willing to commit #4 overall money since no one jumped out as a can't miss prospect), they had no choice but to the make the pick. At the time, they were operating under the assumption that the 2008 season (which was marred by many injuries) was just an abberation. Tim Ruskell (the GM at the time) felt that the team's playoff window was still open. Hasselbeck was their starter (eliminating the need for a QB) and it was assumed that Walter Jones would return to full health (eliminating LT from the discussion). Thus, Curry (being the "BPA") was chosen.
Its hard to say that Curry is a flat-out bust, but it isn't a stretch to say that he has underwhelmed. Alot of people in the Seahawks fanbase expected the talent to match the selection spot (and rightly so), but that hasn't been the case.
Curry's career has been essentially defined by his physical prowess, which allowed him to overwhelm college-level players and make plays. In hindsight, it would have made more sense to peg Curry as a mid-lower 1st rounder simply based on potential.
Having said that, it is very rare to find ILBs or 4-3 LBs who are worthy of Top 10 or Top 5 picks (I am assuming there are several examples that disprove this, but I can't think of any names right now) based on the fact that pass rushers hold more perceived value.
As far as Curry goes, he isn't a bad character guy (Tim Ruskell's one flaw was that he valued "character" over talent). The coaching staff (including Jim Mora's staff in 09) tried using him all over the place in order to tap into the play-making abilities they saw at WF. They tried him at the 4-3 OLB, 4-3 DE, the LEO (which is more or less a modified OLB position), and DT on passing downs. None of which have yielded much in the way of results.
Since the end of the lockout, Pete Carroll has been cutting or modifying the contracts of players who he deemed to be overpaid (and rightly so) that were leftovers from Ruskell's regime. He's only willing to pay top dollar to "his" guys (Rice, Miller, Okung, Earl Thomas) or reward players from the previous regime who have earned it (David Hawthorne, Brandon Mebane, etc.) Since Curry was not Pete Carroll's pick, it made little sense for him to be paying 10-15 million (or whatever) per year for a guy who has not made much of an impact nor loved up to his billing.
To sum it up; Curry is not a terrible player. He is simply the victim of draft hype and a new regime. If I were Bill, a 4th or 5th Rounder would be more than fair to see if he can unlock the Curry that we all saw at WF.
P.S. Sorry if this was a little long. Just wanted to give a you guys better perspective.