On the contrary, my memory is that while Posthaven had a few front page posts as it launched and has since been mostly left alone, app.net has had a constant barrage of them during its "kickstarting" and afterward. Your own Google link seems to bear that out. There are certainly commenters in every thread dismissive of app.net - probably more than of Posthaven, since where Posthaven's entire reason for existence is to have a modest and obviously sustainable business model, app.net's goals are somewhat unfocused but extremely lofty - but there are many praising it in every thread.
What does Posthaven even have to do with this article?
I'd recommend you do a Custom Search starting from 2/18/13, the date Posthaven was announced, in order to do a fair apples-to-apples comparison. The results are much different. :)
Although app.net has the advantage of time, including the launch hype about Posthaven but not app.net is quite unfair :)
Anyway, I think number of Google results is a bad measure, since it counts posts and comments equally, and seems somewhat arbitrary in its choice of comments.
What does Posthaven even have to do with this article?