It's "good business" in that you maintain higher profit levels.

It's "evil" in the sense that you are deliberately and dishonestly screwing employees in the worst possible way. It's exploitation.

The very reason this is illegal is because it's quite obviously morally and ethically wrong, but people are motivated to do it anyway.

The only difference is that on a small scale, you might not be caught, or you might be able to bluster your way out of the consequences.