It might be more accurate to say that comments alone don't make a community, at least from my personal experience. But then, my major fandom lacks a lot of people who create raw material where as the few people who do create generally get at least some feedback.

For me right now, it's the lack of fellow creators that's making me drift away from my pet fandom, not the lack of comments. I could see it being different in other types of fandoms or for different people, though.