Getting a situation from 90% optimal to 91% is very difficult and produces an improvement few care about. Getting a situation from 20% optimal to 50% is usuall

Getting a situation from 90% optimal to 91% is very difficult and produces an improvement few care about. Getting a situation from 20% optimal to 50% is usually relatively easy; getting to 75% is a giant pain, and either result will get you hailed as a hero. You also deal with the politics with the disengagement of an outsider, and you're gone before it can suck you in too deep.