Even the process of quitting is broken in the U.S!

I find that when I am lucky enough to find a better paying job and go to quit I am anxious about giving them my real reason. Employers have all the power even when you quit. If you say something remotely negative they could be a bad reference moving forward and ruin your potential future jobs. Not even mentioning the fact of giving two weeks, and they fire you on the spot. Quitting should be a momentous occasion but it is fear inducing and the employer never will take constructive feedback.