"Should be necessary" has nothing to do with it. "Is it effective?" is the appropriate question. People respond to positive messages. That's a fact. It's not a weakness of their character or lack of motivation. Guys want to win; they push themselves to the limit to win; but they need to learn how to win; and they need to develop the right mindset to win. He'll do the former at practices throughout the year, and he is starting on the latter with the redecoration of Gillette. He is providing a clear message that nobody has accomplished anything yet and letting the new guys know that he believes in them without resorting to some kind of Stuart Smalley BS, "cuz gosh darn it, Brandon - people like you."
Like folks have said, that's leadership.