I always thought I was cynical about people, but rilla and coccobill make me look like an optimist.

Absolutely beyond 110% not the case. The average joe is no better than chance at telling between an expert and an expert fake. If you can flood the conversation with more expert fakes than there are experts, you can robustly direct the conversation away from the truth. Profitable cig companies would have an interest in controlling the conversation, truth-jockeys without a profit motive would have no chance to compete.
Do you really believe that corporations are this powerful and that individuals are this weak? You don't think the evidence would pile up pretty quickly that smokers are a hundred times more at risk for a hundred different medical conditions? Why do you think that the cig companies would have infinite power to control the conversation, given how unbelievably expensive that would end up being? Yes, they're going to market their product and down-play the risks, and they'll spend as much as necessary to maximize their image without cutting too much into their profits, but there will be limits to what they are capable of.