That's often true, but the ability to express an idea succinctly can also be a sign that the author has thought through the idea and his words very carefully.
("I would have written a shorter letter, but I did not have the time." Blaise Pascal.)
Which I think this tweet did. It captured a whole lot of wisdom and experience into a small package, but it didn't match every situation. Rules of thumb like this one are usually like this.
