Initially I was against it in your first paragraph but I started to agree. People do go out of their way to leave a bad review, the others are left enjoying the

Initially I was against it in your first paragraph but I started to agree. People do go out of their way to leave a bad review, the others are left enjoying the product (most of the time). The only moral issue is perhaps that the method doesn't disclose what people are unhappy about to the public, who might be looking at the reviews. However, you're not preventing people from leaving a negative review with criticism, you're simply providing a way for feedback to be provided directly back to the developer which is good and there's no issue with that.