I respect your opinion.
However, many of your claims are not supported by the text.
As far as character development goes, most characters see a large amount of development. Dally, for example, goes from being a tough guy to caring deeply about Johnny. Ponyboy goes from a kid who follows the crowd to someone who thinks for himself and learns that fighting is not the answer. He learns that people are people, and it is not just about Soc's and greasers. He goes from thinking Darry dislikes him, to fully appreciating all Darry has given up for him.
The settings were based off of the Author's hometown, so they are not created to be exciting, instead, they were created to be realistic. The characters are highly relatable because while we may not be in similar circumstances, they all feel human emotions that we can relate to.
The unintelligible dialogue is called dialect, and it is a way for the author to create characters who sound more realistic. Most people do not use proper grammar when speaking to friends each day.
The drugs and cussing is to show how rough these kids have it, and how rough they are around the edges. It brings the idea that people are not what they seem to the forefront of this novel.
Lastly, The Outsiders does not encourage dropping out. Instead, it shows the importance of staying in school because Darry gave up his chance at college to make sure Ponyboy does not drop out, and his other friends and family encourage him to stay in school.