I would not categorize it with such a dichotomy.
For one, while there are GMOs who deploy, physicians that deploy as GMOs, and physicians that deploy in primarily administrative positions, most deployments for medical corps officers are to provide medical care in their specialty. Now, the acuity and volume of that care can vary widely, but if you're deployed as a surgeon, they're typically not going to make you DCCS just because there aren't many operations to perform. So, it's not really correct to lump deployment in with being a battalion or brigade surgeon.
Secondly, physicians assigned to MTFs (or better generalized as TDA units) will have varying degrees of administrative duties. Some people will have light duty, in which case their practice may closely resemble a civilian's. Others will have a heavy administrative burden, in which case they are no longer really functioning as a physician. It's a spectrum, and where you fall on it will depend on a number of factors, such as your specialty, your seniority, your location, your bosses, and your willingness to participate/desire for promotion.
It's easy to say that you understand being a physician second and officer first. It's quite a different thing to live it. I was commissioned through ROTC, so I understand fully the idea of officership. I can also tell you that for me, and I dare say most physicians, medical school and residency were transformative experiences that changed me irrevocably. I worked damned hard for a full decade in order to become a board-certified physician, so I see my degree and board certification as necessary tools in order to practice my craft. The Army sees them as framed diplomas on a wall, necessary only in order to have a career as an MC officer. This fundamental disagreement in priorities is probably the primary reason why they'll no longer have access to my services in a just a few months.