I had the exact same thought. I think the map would work way better if states without ban had a significantly lighter shade of grey (or even white)
As is the ones with 1-10 bans stand out by far the most due to the red being so bright (would need to be a bit more desaturated like the others). And the worse offenders are harder to see against the dark grey.
I like that 0 is very distinct, because they should stand out... But everything else should really be a gradient between two colors, and neither of them should be black when zero is grey....