The new, more economical engines are physically bigger, so in order to maintain the required ground clearance the engines were moved forward and up. This gave t

The new, more economical engines are physically bigger, so in order to maintain the required ground clearance the engines were moved forward and up. This gave the plane a tendency to nose-up in certain extreme circumstances. MCAS was supposed to make the plane behave more like previous 737 models, in order to fulfill the "common type" requirement that would allow 737 pilots to fly it without getting qualified for a new aircraft type. The plane _is_ balanced; it's not like Boeing built an aircraft that falls out of the sky if you slightly nudge the yoke wrong. (Which wouldn't even be unusual; plenty of modern aircraft are completely uncontrollable without computer assistance.) Yes, the problem could've been solved with a re-design of the aircraft- lengthening the landing gear struts, modifying the wings, etc. - but that would negate the point of using an existing and well-tested design. There's A LOT of guilt to go around in this story, but no one can actually be casting doubt on the abilities of Boeing engineers in the fundamentals of aircraft design.