Certainly, but shaming and shunning are interpreted by the human conscience as damage in very real ways. You're not wrong, but I think modern sensibility has such an adverse reaction to using shame as a deterrent that we refuse to call things out as shameful.

Sure, it only works if the people in question care about your opinion, but building consensus on what acts should be shunned only takes about a generation and a half. Segregation, dog fighting, the list is long. If we really think this is bad for society (and I do) then shrugging and talking about incentives isn't the way forward. Especially in the absence of a mechanic to actually change those incentives.

We absolutely rely on people to act ethically even with incentive systems. Every incentive system is prone to abuse. Also, people are motivated by different incentives. These often boil down to their own ethical/moral values.