And yet he's far smarter than the NCR. Which goes to show how bad the NCR is.
They probably did modernize in the Legion ending. Shit, if they can honor a woman as their new national heroine, they can change their drug policy as well. The Legion was never meant to be a permanent state of being, it wasn't even a Legion to begin with. It was a hodge-podge of tribes that were eventually united under one great tribe known as the Legion, and Caesar himself states that the Legion will have to change once it settles into Vegas as its New Rome. Maybe a few decades down the line, you'll see female Legion soldiers using energy weapons and drugs, fighting alongside the men.