I think the biggest problem at this point is how much Twitter has replaced a core part of how journalism used to function. Back in the day, if a company/organization/famous person/etc was doing something of note, they would write a press release and send it to news organizations, who would then decide how to cover (or not cover) the story.

Now, shit just gets tweeted out and a good chunk of journalism is just putting a few words around that tweet and calling it news. If Twitter disappeared tomorrow and no clone immediately popped up in its place, modern journalism would collapse.

I'm not saying that's a bad thing.