That simply does not follow.
Rather than, "a marine who doesn't make their bed with precision is incapable of precision," think of it as "a marine who doesn't make their bed with precision is experiencing problems that could prevent them from acting with precision in more important situations."
A "no brown M&Ms" situation. https://www.snopes.com/fact-check/brown-out/
(Also, it's a matter of establishing a habit of discipline.)