I tend to look to nature for inspiration in thorny problems. For this one - essentially confirmation bias - genetic mutation seems an attractive metaphor. That is: there's always a bit of randomness thrown in. That could be dialled up/tuned to always include some contrarian answers.

I don't expect we'll all return to the great debating chambers of the past, but it'd be an interesting experiment at least: what would happen if every anti-vax search result included something on the benefits?