It sounds like you do disagree with the comment you're defending, though- they're suggesting that this is a US specific phenomenon. The US may be worse in this regard, but I don't know where to find relevant statistics (looked into this for ~30 minutes), or how you would go about controlling for the US being both wealthier and more criminal than a lot of the world. Would love to learn more about this!
Part of it is justifiable. The value of a prison is threefold. It's a punishment, and in that sense it shouldn't be exclusive to the poor. But it's also a way to separate violent criminals from the rest of the population, reducing further violence. A financial criminal can just be denied access to the industry to achieve that end. And it's an opportunity for rehabilitation, but that doesn't seem to be a priority in the US anyway.
Part of it is justifiable. The value of a prison is threefold. It's a punishment, and in that sense it shouldn't be exclusive to the poor. But it's also a way to separate violent criminals from the rest of the population, reducing further violence. A financial criminal can just be denied access to the industry to achieve that end. And it's an opportunity for rehabilitation, but that doesn't seem to be a priority in the US anyway.