Since you accusing me being a simpleton, you are going to have to explain what you mean.
If the point was to try to understand the reasons for incarceration period, then fair enough, "people committing crimes" would be good enough an explanation. But I think the debate is more centered around "massive incarceration", which implies that there is something special about the rate of incarceration in the USA and that people are trying to understand why that is that the USA are putting so many people in prison for petty offenses, drug use and myriads of other controversial reasons. It also questions the reason why some minorities are so disproportionately represented in that carceral population and whether or not there is a system in place to target them specifically in the response to crime in the country.
I would like to apologize if the phrasing of my answer was a tad snarky, I just found that you were addressing the topic with way too broad a brush for an issue that is so extremely serious, far-reaching and bordering on institutional social management.
It's a shining example of marketing having a negative impact on public discourse.
<sarcasm>You can't blame poor people for not having access to the immunity bankers have.</sarcasm>