I was trying to be sarcastic but they seem related...
The court did not say DUI could not be a “felony.”
The court said DUI could not be a “violent felony.”
Just like embezzlement is a felony, but not a violent felony.
“If DUI isn’t a felony, but running over someone while driving drunk is, does that mean attempted armed robbery isn’t a felony unless someone gets shot?”
Attempted armed robbery is closer to attempted running over someone. In both cases the attempt involves underlying intent to harm another person and could be attempted drunk or not.
DUI may be done merely in an effort to get home. There may be underlying danger to others (or maybe not) but no underlying intent to harm. Most people who are DUI would probably rather get from one place to another without doing harm, and attracting the subsequent attention from the police.