YC is all about investing in companies that solve a problem. Gaining early adopters is a problem that product builders have, and Product Hunt seems to be doing a good job of helping to solve that problem.
Early adopters aren't people that read TechCrunch or Product Hunt. Those are just geeks. Early adopters are a specific segment of a customer population that have the pain the most and are willing to try novel solutions.
While it is a problem without any real stats on how many users ares converting and how many are actually becoming daily users, its nothing more than a reddit subreddit.
I agree. Many founders spend much of their time networking in order to gain early users. Not all of this time can/should be eliminated, but if founders can be more efficient in gaining initial users that is a good thing.