The Bitcointalk forum has got nothing to do with it. In fact, we are seeing a drop in activity on Bitcointalk year after year while bitcoin's value is increasing. More people are leaving than coming. And many who come, ran across Bitcointalk by accident when they were looking for solutions to a Bitcoin-related problem. It's not entirely the forum's fault. The new generations aren't fans of the forum culture. They prefer other and faster ways of sharing information.