Frankly the biggest problem with twitter is journalists taking it seriously and abjuring their actual jobs of explaining what's going on in the world in favor of low effort no-information bullshit like "person X said Y on twitter." Literally nobody else with a life and a day job does. It's the comments section they removed from their websites.

The "muh stock market" argument is stupid; there are punters who take it seriously, and obviously, it's a great vola signal for automated traders. So what? Rumors were propagated before twitter and will be propagated long after it goes the way of other useless companies like pets dot com.