The law is, first and foremost, a way to keep shitty people at bay. It's still people who are the problem, but since we can't just agree to all be kind to each other, we have to invent ways to either sanction or use violence (note: that includes police) against those who make things worse for everyone else. We need laws, but they are incomplete solutions, not source of the problem. And sometimes they can be weaponized exactly by the individuals we'd rather put the law against.
The blame here is on all bosses who can afford to pay their workers decent wages, but don't. And - personal opinion incoming - if your small business can't employ people for decent wages, it's already financially unsustainable, you just put it on the shoulder of your workers and add insult to injury by trying to also take something for yourself. Should the state do more to support small businesses, to make sure they can pay good wages and be sustainable at the same time? Yes. Is being a small business an excuse to abuse workers? No.
That's why there are things like minimum wages. Businesses must respond to their workers.