Capitalism is NOT a system for reaching optimal outcomes. Capitalism is a system for optimally aligning consumer values and producer incentives, as well as the production process.
Consumers are still able to make harmful choices, and even when they act rationally individually, overall outcomes can still be negative, or at least suboptimal.
Under capitalism, we still must question whether consumer values are correct, and when necessary, advocate for organized change by consumers, producers, or even the law, when harm (ie torts) is not recognized.
The difference in all other systems is that demand and production are not aligned, so we must criticize both the market outcomes and the disregard for consumer values.