No, you are free not to accept inadequate pay, just as the companies are free not to accept excessive pay. It's a marketplace, just think in terms of bids and asks.
It's a marketplace until the business starts using a nonexistent "shortage" to lobby government to add more visa slots and create programs to funnel more students into the jobs it wants to pay less for.
It's also a marketplace where one side has much more information and negotiating power than the other.
Of course you are free to do whatever you want, it's the entitlement that pisses me off. Somehow, employees charging "too much" is not ok and totally not the companies' fault, whereas offering too little is great management. Then they wonder why there are six million jobs that they can't fill.
It's also a marketplace where one side has much more information and negotiating power than the other.