Apple can't lobby to make the "Official phone of the United States" simply because there are significant hurdles in place.

Government procurement is a very different beast than most people would be used too. Imagine an organization tasked to deliver the world, but while spending the absolute minimum, and without showing anything that could remotely resemble favoritism in the process.

That's Government. The supplier must be reliable, yet everyone should have an equal footing from which to have a chance to grab a contract.

It has to be cheap, yet must satisfy every requirement necessary to fulfill the procurement's intended purpose.

There must an always also be at least the appearance of propriety in all transactions, or losing bidders have every incentive to challenge the integrity of the decision.

Given the significant hurdles represented by having to jump through all the hoops in winning a Government supply contract, it simply makes more sense to focus mercantile efforts elsewhere where returns can be made with far less risk.

Prisons on the other hand, run into the worst of both worlds. Private prisons don't make money without convicts. So they might lobby for increased mandatory incarceration as a punishment for violation of new laws. You also have operations where prisoners are exploited as slave labor (which is explicitly allowed by the Constitution). Which if you really sit and think about it, makes the threat of increased incarceration as a result of profit-motive for the private prison industry that much more dangerous, as by definition, you are delegating people to a more abusable status in the eyes of the law.

Hard-on-crime stances notwithstanding (I'm not taking sides, just pointing it out), one really needs to take into account on what spending on prisons really says about our society.

Begone yee incarceree!
Ye has't offended in the eyes of Man and God, and to the Pit do we consign'st thee til through suffering that debt is repaid!

Vs.

Your offense has brought you here, being due to the threat to civil society your reckless and thoughtless behavior represents. Through the insecurity you suffer through here, it is our hope that you will come to understand the fragility of the civic construct, and come to see the error of your ways.

Vs. Yet still:

Clearly, our society has failed to incorporate/integrate you in a safe or constructive way. Here you must remain for a period until such time as it is deemed necessary to recompensense for the crime you have committed, or until it can be observed beyond a reasonable doubt that you no longer represent a threat to the civil life outside these walls.

A prison by it's nature does not function as anything else than a container or isolator of men and their proclivities. To create a profit making enterprise around that under the guise of "innovation shall make this system better" is foolhardy, seeing as the law, and punishments for breaking it often preclude any way to operate a prison or treat the offender in a "innovative" way.

The price of a man's years is set by the people already, that is. No private prison can innovate on that except by changing or altering the suffering they experience therein contained from the rest of society. Their Wardens' alone reaping the benefit of the custody of society's delinquents.

Furthermore, even the vaunted Market can be severely damaged by the "free labor" potential generated by prison inmates.

I just see far too much potential for negatives and far too few possibilities through which one could wave a magic wand and both dispel the wickedness of the alleged offenders heart (if it actually exists), and also extracting something resembling justice for the victims should it be appropriate.