The Good: It's easy, if you actually try. It's a good place to find friends. You can learn many things and get a good education(even though you forget it 5 years after you graduate xD). Finish school and your guaranteed not to be a janitor mopping the floors or being a sweaty cook and flipping burgers. . . .you'll be automatically prepared for being the cashier worker ;D.
The Bad: Assholes(people), prejudice people(of all kinds), boring, grueling(like when your sick and have to still go to school feeling bad), knowing your future is in the hands of this boring crap(lawl), having to force yourself into a "group" or being forced into one.
The Ugly: Retarded people(no offense. . .), ugly annoying people(most of the ugly people I know are annoying. . .not saying ugly people are annoying just that most of them I know are).
To be honest if everyone in the world actually tried to get a good grade, I bet people with an IQ of 85 and up would achieve it easily. The thing is school is so dam stressful and most of the people inside it are total assholes and ruin it for many others. Not only that so many people want to "fit in" which could make them think that it would lower their stress significantly. The people who achieve it end up being their own worst enemy and usually act like assholes, the people who don't achieve it get seriously stressed by keep trying and possibly depressed, and the people who don't even go for it live a terribly isolated, boring, and a somewhat wasteful school experience.
Sucks in a way, but you have to do it unless you want to mop floors or flip burgers for a living. Not only that but the truth is I won't take many things I learn at school close with me. I wonder why those super smart people skip so many school years? Because they want to get it over with and hurry up with their life and do what they actually want to do, not study at crappy school 6 hours a day but go to college and pursue what they want.
Too much thought went into this post, ending :P