100% this! I'm seeing more and more tweets that are entire pages of text in JPEG format. I can't really say it's a failed medium, because obviously Twitter has massive usage, but it doesn't really seem like progress.
Sadly, because tweetstorms are getting more and more popular. I think it gives people a superiority feeling ("aha, look at how much brilliance I can convey in so few characters!"), whereas the reader is just frustrated.