I was more responding to the concrete “this is the way it’s done” vibe that I got from the post I quoted. I don’t doubt that this happens, and of course physical networking is important
I guess people read into things what they want to read into things, if they’re looking for an argument. No, it’s not the only way that things get done. But, in my opinion, the higher up the food chain you want to go, the power of a personal introduction (which could be via Twitter, FB, phone or email)is still more effective than an unsolicited communication.