My group does this, but not because we're evil. Larger groups often have fellowship trained radiologists who are experts in a certain sub-specialty, for example Neuroradiology. Smaller groups are usually all 'general' radiologists.

If we can read pediatric brain MRIs more accurately from across the country than the local small group, why shouldn't we?

One additional note. My 'customers' are not really the patients, my customers are the physicians who order the studies. Most hospitals and referring physicians demand that I be available to speak with face-to-face, so there are parts of radiology that cannot be performed remotely.