@DrorBedrack @Daojoan Regardless of one's views on your philosophical tangent, you've basically turned the OP's message 180° from what it was saying.
It's not that "truth"/validity doesn't matter, but that having a "marketplaces" is utterly the worst way to foster it, because the evolutionary pressures reward "memetic fitness" not "truth".
Same reason why ascribing moral goodness or desirability to Darwinism in other contexts (biological systems, social systems, etc.) rather than treating it as an adversarial property that's amoral is so bad.