If someone steals food or a small amount of money because they go hungry otherwise, that is absolutely a case where they need help.

But those people are already victims, and don’t need rehab targeting their behavior, neither are they dangerous, just pushed into it by circumstances.
If you have to steal food, you don’t belong in prison for that in the first place.

The only counterarguments

I’ll add another I think you might agree with.
If someone gets raped in prison, there, necessarily, has to be someone who rapes them. This will likely just be a physically stronger rapist, who on the other hand is even getting some enjoyment from prison. And what’s going to happen when that person is released?