I couldn't disagree more. How is using a tweet to support an argument negative in any way, shape or form? It's no different than quoting someone as long as it's a legitimate source.
It isn't as if I or anyone else is using tweets from random people. They're experts whose opinions and statistics can be used to support an argument.
Twitter is a platform that is constantly growing in terms of size, scope and popularity, so it would be silly not to utilize it. It's only going to become more prevalent in online journalism moving forward.