The laboratory has always been on the fringe of medicine and is one of the more inscrutable concepts of health care that number crunchers and administrators never quite get a firm grasp of. This goes with the more understandable concept of scrutinizing clinicians who generate revenue based on patient visits or procedure/operations which lead to more analysis by those HR/financial people when reviewing hospital economics. Don't get me wrong, they know there's gold in 'dem hills, but almost all labs in the U.S. are profitable and a lion's share of this comes from the CP side. For a hospital-based laboratory lab to not generate a net positive cash flow, it would take epic amounts of incompetence on the level of Chewy from 'The Goonies' at the helm.
I'm willing to bet most administrators have no clue what the average pathology group is billing. Even if they did have an idea, because of the reasons listed above, that is usually enough to keep them happy and/or to have no interest in looking at our RVU's. Things are changing though and this model is vanishing as the trend of outsourcing/centralizing pathology as well as more hospital-employed physicians is growing.
Being left out in this case is a good thing. The last thing I'd want if for the CFO to have a meeting with me and my partners and say "Well, the hospital is looking at new ways to increase revenue so we decided to take over the billing for your group!". Translation, you'll go from making bank to a pay cut and to go with it you'll have a nice tall glass of stfu, plus with the bonus of being a hospital employee, you'll have to pee in cup for random drug screens.