I don't even think Burke was criticizing the signing so much as he was just curious to see how the Leafs were going to use him. You can't really criticize signing a guy to league min salary for 1 year. By the way, I don't like Burke either I am just saying here he wasn't that wrong initially.
The difference is that as fans, we are on the outside looking in, compared to decision makers
is in the totality of the information that have at their disposal. From conversations with the player they sign to coaches and scouts, clearly the Leafs decided that Thornton, either before or after they signed him; was going to be utilized higher up in the lineup than most expected.
I stated after the announcement that I didn't think Joe was a first line player at this stage in his career, but "maybe Joe doesn't agree with me". Based on his performance, it's safe to say he doesn't. He still has what it takes to play production minutes, especially with top end talent. If it doesn't go as planned, he can easily excel lower down the lineup, the entire team is pulling the same cart as long as they do so.