Conventions do not give the MSM as much clout.
More importantly (to them), conventions mean you don't have multi-million dollar advertisment buys.
Remember folks, when the media is yelling about "money in politics", the vast majority of this money goes directly to them. Political campaigns are propping up the lamestream media in a major way. That's why it is in their best interests to keep the nation so evenly divided. It makes more money for them.
That is an excellent point.