I used to make the same argument. Then global warming busted wide open. . Now the razor is “they are lying”.
Sorry, but the AGW and JournoList scandals support my position, not yours. They were unable to keep their secrets for long.
And there are a LOT more people who can rationalize to themselves lying about AGW or suppressing negative stories about Obama than planning or covering up the mass murder of first graders.
Actually, if you’ve followed Climategate, you understand that the number of people actually involved in a conspiracy to block heterodox researchers from publishing and so on is very small. Most of the other participants don’t have the scientific training in climatology and are just following their lead because shutting down the industrial capacity of the West falls in line with the left’s agenda, and has done so for decades before AGW.