I wear a jacket pretty much every day, save for the warmest days in the summer. If nothing else, I like putting stuff in my jacket pockets rather than my pants pockets.
And, sure, if the jacket I wore also managed to give me that bit more protection, I would take it. But that would not be why I'm wearing it. I wouldn't wear it for its protection, I'd simply appreciate the protection it offered should that need arise.
Because, and here's the real distinction, were I at risk for being attacked, by anything, at risk enough to where I'd say "we're going down town, let's armor up", I wouldn't go.
And, yes, I'm being a bit disingenuous here, because I do ride a motorcycle, and I do armor up, head to toe with gear that makes me look like the Michelin man. I have more protection than a football player. My gear is heavy, spectacularly unfashionable, and not particularly comfortable off the bike. I can argue that I do not have enough, I still do not have an airbag vest, which is on my list. I just haven't pulled the trigger yet.
So, why is gearing up to ride a motorcycle different from doing something similar to go out to dinner? Well, mostly is a matter of intent, what risk you're preparing for, and where it comes from.
My riding gear to protect me pretty much from accidents. To protect against mostly unconscious actions. I'm not gearing up because I fear someone will chase me down and knock me off my bike. I'm gearing up because someone may be driving distracted and unintentionally knock me down.
Driving is typically not dangerous because folks are out to cause harm to each other, whether to me specifically, or someone nearby by happenstance. It dangerous because of distraction, mechanical failure, bad reactions to a road condition, or whatever. Sure, there's always stories of things like road rage and other nonsense, but it's not prolific enough to plan for specifically outside of basic guidelines "don't antagonize crazy people on the highways".