Apparently you don't work with internal medicine residents. While there are primary care focused IM residencies, most IM residencies are heavily concentrated on inpatient services. What this does point out is that primary care specialties are not generally qualified for inpatient services. You can see this born out in the use of Family Practice Physicians in hospital medicine. At one point there was a significant FP presence in hospital medicine. However as FP residencies emphasized outpatient ambulatory care it became harder and harder to show training and expertise in inpatient medicine. In most healthcare systems FP cannot be credentialed for inpatient services without a hospital medicine fellowship. The same split occurred in emergency medicine which was largely the domain of FP. With the establishment of EM residencies there are fewer and fewer FP physicians in the ER.
Does that mean that FP doesn't do ER or inpatient, of course not. On the other hand the more standardized an organization becomes the less likely they are to credential FP for inpatient or EM. It doesn't matter how long they have been doing something or talented they are, from a liability standpoint the system would assume tremendous liability if they credential them. You wouldn't credential a family practice physician for critical care. They don't have the education, training or credentials to perform critical care just like you wouldn't credential a infectious disease physician to do spine surgery. Are there family practice docs rounding in ICUs and performing surgery in the hinterlands. Absolutely. Is it dependable if something goes wrong. Absolutely not.
As far as scope I defer to Carolyn Buppert: "What is the level of care required for my patients? If primary care, hire an adult-gerontologic, pediatric, or family NP, or a PA. If practicing psychiatry, hire a mental health NP or a PA who has specialized in mental health. If the practice is gynecology, hire a women's healthcare NP or PA who has specialized. If the practice is hospitalist, hire an NP certified in acute care or a PA."