USPTO acts as the gate. If a patent is overturned, in theory the USPTO should be the institution paying for their diligence failure. Up until the patent is iss

USPTO acts as the gate. If a patent is overturned, in theory the USPTO should be the institution paying for their diligence failure. Up until the patent is issued, all costs are on the applicant. Why should the costs of an error by a regulator also be on the requestor?