You're right many people are too busy or lazy but that's why they aren't rewarded as much as people who put effort into quality. I don't suggest flagging anyone or banning them but I am definitely not alone when I tend to unfriend low quality posters because I don't want to see junk clogging my feed like Facebook, Twitter, Reddit or most of the internet for that matter. The beauty of Steemit is it is customizable and you can choose to be annonomous yet still be heard by like-minded individuals.