I agree with most of your assessment and would add that I find that so much "meaningful content" is now almost required to be packaged and "sold" as a Twitter bite. So much meaningful and necessary content is not reducible to 140 characters, but gets overlooked because it wont garner the social points that it needs to make the poster "popular" or the content recognized.

Even our political campaigns are now reduced to tweet wars, and platforms seem to need to be (lossy) compressed into 140 characters, or maybe 3 if it's very important. If you have a string of longer than 3 tweets, you lose a majority of your audience.

Twitter is a good tool, but simply should not be the de facto anything other than short messaging, in my opinion.

That social approval is what defines what's socially acceptable everywhere.

Twitter has expanded the boundaries of politically correct / acceptable speech, by enabling that brown nosing and echo chamber re-enforcement and not cracking down further on what's acceptable speech on their medium.