Some physicians, facing daunting business costs, decide the price of autonomy isn't worth it. Only about one in three is expected to hold a practice ownership stake in 2013.
Dr. Veronica Note:
Another side to physicians leaving independent practice is more job loss. Closing or consolidating practices means that thousands of jobs are lost which may not be recouped quickly as the whole healthcare system is doing a lot more with a lot less.
Also, the choices that people have for choosing care are becoming more and more limited. As the ACA appears to be giving more people access, what may be happening is less access as doctors leave/retire or become employed and cut back their hours and patient load.