The 'look' seems to dictate what a lot of riders wear.
Most have a dress code, outlaw biker bad guy, road racer, motocross racer, and I am not sure what the T shirt on a sport bike is, the squid look?
Its rare, but I have also seen the rugged adventure rider, new gear and plenty of it (on a very hot day), very clean BMW adventure bikes, at a very trendy spot (New Hope PA). Not a speck of dirt was seen that day, or ever.
Like I stopped doing whatever I was doing, put a helmet on, and jumped on the bike.
Jacket in the cold/wet, sun screen in the sun, boots in the dirt.
That has worked for me for the last 40 years.
I know its kind of stupid, but I want to ENJOY riding, I do not want to spend a lot of time gearing up and being uncomfortable on a ride, and I often jump on the bike for very local short trips to the store and so on.
Its just as easy and fast to jump on the bike as it is to get in the car.