The point is that most fansites never take off in a "big" way. Most of the ones that actually survive over the long haul never actually try to take off in a big way. Part of why people reacted to your response to Revenant's comment is that HBO is actually a pretty good example of a fansite which has had pretty large popularity at times.
You answered your own question, though, by calling your plan "crazy ambitious." It's an accurate description; you come in here saying that you want to do something that is (somewhat intrinsically) extremely hard to do, and presented no clear vision of how you intend to do it.