I think their point was that leaning allows you to corner at high speeds, and that not being able to do so would discourage dangerous driving behavior.
I'm not sure I agree with that, but there is some logic that to thinking that a larger, slower, clunkier vehicle might lead to fewer fatal accidents.
But... it doesn't make sense. Sure, maybe a faster vehicle can indeed be more dangerous, but I see no reason why a vehicle that can turn better would be more dangerous.
A vehicle that can take the same corner at higher speeds can also take more difficult corners at lower speeds and is a lot more forgiving.
I'm not sure I agree with that, but there is some logic that to thinking that a larger, slower, clunkier vehicle might lead to fewer fatal accidents.