The survey was strategically done in late Summer. I concede some people could still do their shopping in Hamburg's raining 2°C, but I'd guess the comparison charts would not be as cheerful.
today it was 25 deg C at 6am and over 32 deg C at 5pm when I would have to ride home.
I'll ride it every now and again, but honestly its too much to do on a regular basis.
And my kid/dog sit nice and dry under the hood of the cargo area.
I've ridden motorbikes for many years in a subtropical city, had all the right rain gear and it still sucked to ride in the rare +5°C rain. Even southern Germany gets snow and icy rain, good luck clothing for that.
Edit: of course it already exists: https://newatlas.com/entrosys-motorcycle-airconditioner-revi...
https://en.wikipedia.org/wiki/Liquid_cooling_and_ventilation...
A much bigger problem here is cycling paths not being maintained in the winter and salt on the roads.