I like Twitter because it forces people to be concise. There are already plenty of places on the web where people can post long thoughtful articles or op-ed pieces.
But it doesn’t lead to any meaningful discussions. I’ve tried using twitter for some time now, and you end up sounding a lot more angry when you spend the 20 minutes trying to get your thoughts into 140 characters, and you’ll have to use a horrendous amount of abbreviations. There’s no space left for polite "hey, sorry, I disagree with your thoughts on [long name of a project], I’d think you could do [feature] better…
Obviously there's no right or wrong way to use Twitter, but I generally don't follow people who do more than post inane status updates like "i love tacos lol" or links to mildly interesting news articles. For me at least, that's all I want Twitter to be, and it does that admirably. If I want discourse theres room for that pretty much anywhere else on the Internet.
I suspect the majority of the problems people have with Twitter stem from expecting it to be something that it just fundamentally isn't and can't be. If you use Twitter with a desire for serious engagement with others you're almost always going to be disappointed. If you treat it as a place to put silly 140 character messages out into the world whenever you feel like it then it's much more fun. And weirdly, much more useful.