You object to signing a contact with an entity representing your workers, and dealing with employees according to rules set out in this contract.. I suspect you wouldn't think twice about signing a similar contract with suppliers or customers.
My only conclusion is that you prefer to deal with employees individually because you can more easily manipulate them by doing so. You enjoy the power of being the owner and being able to play favorites, taking advantage of the inherent weakness in an individual's bargaining power and the lack of any enforceable written criteria governing your rule. You accept the occasional loss of an employee able to find better conditions because you know you will always find a replacement.
Of all the inputs to your business - labor, materials, facilities - only labor is to be forced to deal from a deliberately weakened perspective.
You must be a joy to work for.