Second, the "self-interest" argument doesn't excuse shitty behavior. It might be in my self-interest to steal my neighbor's wallet he forgot outside. It has money in it! Doesn't make it a good idea nor something I would consider as a "self-interested" person.

Plus, it's also in my self-interest not to contribute to lowering the bar of a review system. As someone who uses Amazon and other review sites, I don't like the idea of phony reviews, so even if I worked for a company that "depended" on these reviews, I wouldn't feel good about adding to the problem (nor would I feel good that my employer supposedly needs to rely on falsified reviews).