The problem is some folks don't know the difference between "networking" and being a pain in the rear end. At Eastercon I saw some rather aggressive networking by some want-to-bes and lower to mid-range authors that made my hair curl.
The thing folks need to remember that as such gatherings, yes, there is business going on, but there is a lot of socialising, getting together with old friends for a drink and a laugh. The last thing people want is some idiot to crash their group of friends and bang on about "their" book.
I was fortunate to be in the midst of a number of gatherings in the bar, one included a top agent, who had rejected my last work lol... At no time did I ask him why
Or even mention the fact that I was a writer. It did not feel right during any of the conversations, as they were mainly social in nature and people were relaxed. You could see people stiffen if someone started a pitch.
Though many of the late night talks were of course about the subject in hand.