I'm guessing the law is there because an employee being forced not to take their holidays is also unlikely to defend their rights against their employer. ie rather than have the employee prove bullying, they force the employer to prove it wasn't.
So if an employee doesn't want to take his or her holidays they must be forced to do so.
What business is it of the state to interfere with someone's personal choice to work?
I can understand if the employer tries to stop the employee taking leave but if neither party wants the holiday then why force them?
I'm guessing the law is there because an employee being forced not to take their holidays is also unlikely to defend their rights against their employer. ie rather than have the employee prove bullying, they force the employer to prove it wasn't.