Intonation and meaning is lost over the Internet, which is often frustrating. I think this is exactly that kind of incident.
From my pov, when I come to a person about an issue and they respond with "as I noted in the other thread..." it can come across as somewhat gruff and dismissive. I totally get quickly clearing out a ticket and dealing with it simply, but the brevity and tone of the response made me unsure about how I flagged the issue. I immediately wonder if I've frustrated the support guy by giving him further information about the issue. It's certainly an inconvenience to get a dup, perhaps the support guy doesn't welcome updates on tickets? I'm left to wonder whether I've overstepped by supplying more info, and worse, I have to question if GitHub support cares about my response or if it's just been put in the bug bin of despair.
So, all things considered, you guys are doing fine, but maybe are thinking like devs rather than support people. Perhaps that is appropriate for GitHub: devs are your target market. Actually, my biggest beef with your support so far is I never was able to clear out a question about image linking in markdown files in a GitHub repo. Right now everyone in my startup has to add raw blob link to every single link, and this just seems like the wrong pattern. Why should I have to prepend https://github.com/.../../blob/master/.../images/IMAGE.jpg?r... for every image I want to link in our flat file wiki? The last communication I had on the issue was never answered, so as far as I can tell, this is the only way to get images to show up in markdown files...