Why do nonsurgeons always casually refer patients out to surgery even when it is obvious patient is not a surgical candidate?

Unclear: I'm not sure that it's always "obvious" if someone is or isn't a surgical candidate. I think that if a patient has a problem that requires operative intervention, the best person to determine whether or not the patient can undergo the procedure is a surgeon. That's our job, and that's why they call it a "surgical" practice and not an "operative" practice. You need to know who not to operate on.