Every hire is a chance taken for both sides of the transaction. This argument is tired and can be spun another way: a new employee is a blank slate. The employer will define a working method that cannot be compared and judged based on experience (they have none). The employer may even benefit further from a fresh perspective on working methods.

Let's push it further: can we say the same for very experienced employees? Isn't the employer taking a chance on the employee being willing to learn and adopt a potentially different workflow? Maybe we deduct from the value of a highly experienced employee due to the likelihood of them being stuck in their ways. Oh wait that's ageist now isn't it.. Funny how that double standard works.