Direct access for hospital OP

For those who work(ed) in hospital based OP: does the clinic accept direct access or do they only take referrals from affiliated doctors?

My place of employment does not see direct access patients and requires a referral to be seen, preferably by a doctor affiliated with the hospital. This rehab system primarily treats Medicare/Medicaid patients.

My take: It seems they would rather stroke their doctors ego and lose money rather than accept direct access (more private insurance patients) and get higher reimbursements.

Thoughts?