An example of what diagnosis and treatments that exemplifies your
point would be more beneficial rather than making a general statement
of increasing referral volume. In regards to patient management and
use of referrals, from a specialist view this may seems easy and
straightforward. However, the difficulty lies in the patient demand
and expectation. As a primary care physician I have had patients
demanding specialist evaluation for stage 1 hypertension.
In this country we pace in front of the microwave, and the general
population has a distrust of their intellectuals, ie. Conspiracy
theories as exemplified by anti vaccine movement. This and coupled
with an overdeveloped sense of self entitlement, have driven the
proliferation of specialties and subspecialties. This has resulted in
patients and physicians believing that quality care can only be
achieved by a specialist attention. It is not always a failure of
primary care but rather to often the patient’s unrealized outrageous
expectations that prompt dissatisfaction.
A dermatologic example would be lichen simplex chronicus. It is
difficult for patients to accept that their scratching behavior
contributes directly to their problem, let alone that simply changing
their behavior and the use of an over the counter remedy such as
Vaseline can actually alleviate symptoms and can eventually result in
cure. But undergoing this treatment plan requires time and effort by
the patient all of which will contribute to dissatisfaction and thus
generating comments like, “my PCP does not know what he is doing.” I
admit this is a little over the top comment but it has happened.
Also, dissatisfaction goes both ways. In the area I am at a derm
appointment is difficult to obtain and I have had patient return to me
saying that the issue for which they were referred to has resolved
before they were seen. I would argue and maintain that strengthening
in a cooperative way the knowledge base of primary care physician
would be a better solution rather than increasing referral volume just
because. As such, many times even after referral a patient sees a
physician assistant. How is a physician assistant, better suited to
address the needs of a patient that a primary care doctor can not?
After all, dermatology is a pathology based field and a biopsy can and
will often arrive at a correct diagnosis and if not, will point you in
the right direction by eliminating others. After all this is what the
physician assistant will do since often they are on production based
compensation structure and it behooves them and their dermatologist to
perform more procedures. Why cant the PCP do this in house and phone
consult a dermatologist…perhaps because there is no financial gain?
The barrier to specialist is not necessarily due to lack of referral
but also due to insurance issues such as utilization review and prior
authorization steps. These I think are the main culprit to specialist
access not PCP ego and non referral. But this is a bigger issue one
that is being addressed by congress as of this writing and hopefully
will address patient access to health care. But his is another and
bigger discussion.
Regarding the medico legal aspect of your argument, simply referring
does not alleviate the PCP from legal pitfalls. The quality of consult
is certainly taken into consideration. So, if I refer to a bad
consultant one with multiple legal problems for example,  I will be
held responsible for not doing due diligence regarding my consultant
and therefore legally responsible for a bad outcome that may happen.
This is certainly not mitigated by the prolific use of physician
assistants by dermatologists.

As a primary care physician, I absolutely agree with your perspective, that a speedy referral needs to occur once the primary care physician is out of their depth.  On the other hand what you see is skewed - you are not seeing all the primary-care-appropriate skin conditions that are treated successfully.  From the primary care perspective, the practice that interferes most with quality, continuity and appropriateness of care is for one specialist to refer a patient on to another specialist if he is faced with a problem beyond his comfort zone.  The better approach is to communicate back with the primary care physician and decide jointly on the appropriate next step - allowing the primary care physician the role of cordinating the activities of multiple specialists seeing the same patient.