To be fair, Stalin had a habit of just killing people instead of sending them to the Gulag. Not that it excuses the US incarceration rate but your comparison isn't very good.
It was intended to be offensive. Although, the actual numbers are quite disputed and most of the ones we hear should be considered propaganda. Besides which; we're hardly ones to point the finger over genocide these days (Iraq, Pakistan, all those Afghan wedding parties).
To be fair, Stalin had a habit of just killing people instead of sending them to the Gulag. Not that it excuses the US incarceration rate but your comparison isn't very good.