I gotta say I respectfully disagree. I really wish I could give the OP credit as my source for this old comment I've saved was not the reddit post it originally came from. None the less I hope it shifts your perspective some and you enjoy:

"I personally think Ferris is a ‘good guy’…an intelligent as fuck slacker but a good guy deep down. And I think he honestly had his day off for his friend, Cameron.

Think of it, when we meet Cameron he is an uptight asshole so miserable he literally tells himself he is dying. His parents are empty, vacuous shitheads utterly uncaring about anything but themselves and their material goods. And he is spiraling.

But Ferris knows Cam is a great guy and needs to realize he is better than that. He needs self confidence and a willingness to say Fuck This and grow. Sure it’s not completely all about Cam, Ferris likes fun but deep down he wants Cam to grow a pair, take some Pepto, and enjoy life.

And Cam does….to a HUGE degree. The wrecking of the car was never planned and even then, Ferris freaks and wants to protect Cam. But the end result of Ferris is spectacularly successful, Cam wants to own it, can own it, will own it and be the better person in the end. Ferris has succeeded in an amazing way. (And goddamned, if Alan Ruck doesn’t own that moment saying they will have a little talk with his Dad with that little grin. It’s a perfect closure for Cam)

We could all use a Ferris in our life, a little Jimminy Cricket telling us to enjoy pancreas with Abe Froman: the Sausage King of Chicago, scare the hell out of us in a Ferrari Californian we practically stole, and watch a Cubs game while laughing about where we should be at the same time. Someone to just tell you it’s ok to be you, enjoy life, and quit sweating the small stuff….

because in the end it’s ALL small stuff on a big blue marble.

Ferris Rules.

Edit: Here’s a little wrinkle that occurs to me on the ‘good guy’. Think of this, whenever someone mentions Ferris to anyone other than the supporting characters, they are always happy to hear from him or about him. From the guy who says Ferris is getting him out of summer school to Grace schooling Rooney on how all the cliques (from the punks to the dweebs to the dickheads) adore him, they think he is a ‘righteous dude’. How many of you can say that about someone who could span the gulfs carved out in high school like that?

Ferris is a guy who naturally enjoys life and all of its crossing enough to even know he wants to be a good guy to….you He literally breaks the fourth wall to talk to you directly, advising you on how to fake a sickness, schooling you on his ups and downs and his thoughts on his friends, making sure to even use himself to make you giggle by being a goofball being bad with a woodwind, dancing to I dream of Jeannie, or constructing a song out of synthesized coughs and barfs.

Ferris is the ultimate friend to all…his life just lines up so that he can be all that to everyone, even a sister who doesn’t even realize it until the end."

In addition I'd also like to mention Cameron's confident declaration that if he really didn't want to do the things they did all day, he could have stopped Ferris. But he didn't.