In any case where competition is limited, the results will be price increases. If the current Health Management Organization movement continues, there will be less and less competition. Currently, doctors are wined and dined by drug company sales reps. No one benefits from this in the long run. Drugs are more expensive, and care is denied to too many.
If you want to look at big-pharma as an arm or even the major part of the medical industrial complex, you can make the argument that the incredible focus on pharmacological approaches to any disease have incredible knock-on effects on the state of health in the United States both medically and philosophically.
Instead of trying to treat the whole person, we have become focused on providing a pill to fix a disease or a symptom and this culture is reinforced on TV, by doctors, and even in the classroom. If you don't feel comfortable making new friends... there's a pill for that! If you want to lose weight... there's always been a pill for that but now there are even more to choose from. Need your kid to quiet down and be more attentive... now there are lots of pills for that.
This is of course just an argument, it isn't difficult to argue the other side either given the advances in medical care and advantages to being able to treat things with drugs.
There is a philosophical argument in terms of the health of a society that it is impossible to pit profits against public health, because they are diametrically opposed. That is, it is more profitable to deny people care than it is to grant it, so public health will suffer if then system is based on generating profits.
You can also see some practical economic issues with government public health systems being part of a for profit system, where the fiscal solvency of programs like Medicare and Medicaid, as well as the overall stability of the US debt situation is subject to a profit system of health where the costs are not within the government's control. This is partly how we got into the current health care situation.
The term "medical-industrial complex" refers to that sector of our economy that makes money off of providing health care. This is a pejorative term that implies that the firms involved in this sector of the economy are acting in ways that will help them without providing a true benefit to the consumer.
An example of this might be the relationship between family doctors and specialists. Family doctors might refer people to specialists for tests and/or procedures that are not really necessary. They will do this because this benefits them (the specialists owe them) and it benefits the specialists (they get money). The consumer does not really benefit because the tests were not necessary.
Those who talk about the medical-industrial complex argue that this sort of thing happens all the time and drives up the cost of health care in the US.