I cannot speak for "people", but the OP operates under the assumption that the tower scene is intended as a clue, which means the author communicating a fact about MitD. Given that MitD establishes the rules of the game as "hitting lightly" and the result is creatures punched through a wall, I conclude that the author's intention is to communicate great strength.
Over the years, people who were proposing creatures with lacklustre strength have either attempted to claim that the tower scene was not a clue at all, or come up with alternative explanations, neither of which have ever been particularly persuasive.
Grey Wolf