Given that except for a few hobbyists (like myself), all researchers depend on others taking their ideas seriously for their continued livelihoods, how does this sentence make sense?

Yes, but lesswrong is missing the ecological system of dissenting, mutually exclusive opinions and peer review. Here we only have one side that cares strongly about certain issues while those that only care about other issues tend to keep quiet about it as not to offend those who care strongly. That isn't the case in academic circles. And since those who care strongly refuse to enter the academic landscape, this won't change either.