I'll be candid with my sources - I took a class with Patrick Winston called The Human Intelligence Enterprise where we went over a history of AI ideas. Nowhere in that class did I get the impression that 'general intelligence' is 'wacko amateur thinking'. Maybe the former director of the MIT AI lab just failed to impress upon us the disdain for general intelligence you say is commonplace.

http://ocw.mit.edu/courses/electrical-engineering-and-comput...

Patrick Winston is a disciple of Marvin Minsky. They're considered wackos these days.

Who would you consider the leading authority?

The machine learning/statistics crowd. Some names - Judea Pearl, Tom Mitchell, Pete Norvig, Andrew Ng, Geoff Hinton, John Langford, Jeff Dean. Of course there's many more than that, but these have gained some fame through textbooks/open sources/popular press etc. More generally the approaches taken by Google, like vector space models that power search engines. If Google's doing it it's likely not wacko because they have a low tolerance for tomfoolery down there.

OK, now cite where they think general intelligence is tomfoolery.

They won't, out of politeness and not wanting to make enemies. I will, as an anonymous coward on the internet.