as well as "The Big Fat Surprise" by Nina Teicholz as mentioned.
Each of these paints a fully researched rebuttal to the mainline nutrition science sources you cite. Roughly "All of modern nutrition science is woefully corrupted, since about 1940".
I think its less about a sign function than about showing how optional (i.e. nullable) values work. Most languages have them, and making that possibility explicit is recent best practice.
Promise isnt (yet) working with convicted clients. This is purely a pre-trial intervention, as they keep saying. So supposing that they will be trying to exonerate their clients is a red herring.
Supposing that their motives are pure profit is extra cynical; there are plenty of organizations in the world that do good and still earn a little money.
Since this is all pre-trial, the incentives for Promise are to ensure that they have the best rates possible of a) showing up for trial and b) not committing extra offenses until then. The only danger I see is the possibility that they would over-select candidates and get too many who use this as a way to dodge their trials or commit more crimes. Since either of these harm their ability to do business, I would think you agree that they are incented to minimize those events.
I dont think Lucas applies; its about the weakness of regulations to control actors. This is a new organization that aims to offer an alternative for existing government actors.
Depending on how an organization is constructed, profit is not always "all that matters".
Public Benefit Corporations, as well as Nonprofit Corporation, are possible, and will provide some assurance that the company doesnt turn evil tomorrow.
It could be incorporated as a not-for-profit. And I have heard that there is a 3rd kind of incorporation somewhere between purely-for-greed and not-for-profit, where some profit is expected, but is not the only reason for the organization. Look for "public benefit corporation".