You can't win debates with such people, about biking or walking; there's always another reason why they (and all other good and upstanding Americans) can't possibly walk or bike. When they run out of their own made up reasons, it's "well what about disabled people!"
Like yeah, they maybe can't, are you disabled? No? Well then.
The opposite (that it's not OK to disagree) is one of the things that has driven political and social discourse to its current hyperbolic and occasionally dangerous character. It's the source of much of the so-called "culture war".
So to be clear: I disagree, you are wrong... and to follow the mindset underlying your complaint, "fuck you".
Like yeah, they maybe can't, are you disabled? No? Well then.