No one doubts that Jake Locker is talented. He's athletic, mobile, has a great arm, and has a high level of character about him. It's not about those things, though. During his career at Washington, the Huskies weren't all that successful, having only one winning season (2010).
Locker was surrounded by terrible teams for most of his career at UW. Some people may find that he's a steal at the 8th pick, but lets be serious here -- Locker hasn't proven that he can play quarterback in the NFL with his performance at the collegiate level.
The Titans have taken a huge risk with Locker; Blaine Gabbert of Missouri was still on the board, and his statistics speak for themselves. Either the Titans are smarter than an everyone else, or they just made a huge mistake.