it's just really a matter of preference, need and how you use your bike.
If my bike was just for fun and not my only means of transport and I could afford to run a car as well... hell yeh I'd be sat in the car for the run to work rather than freezing my nads off and risking binning the bike. Granted spending on kit and things like hand guards and heated grips helps but the risk of hitting ice is still there and can be very painful.
Also, even though I'm the grand young age of 26, my body is getting progressively more and more shafted and I don't know how much longer I can cope with riding, never mind the cold. When doctors are telling you to stop riding... they can f**k off.
Winter riding is fine for practicality (I can't park a car at work and buses make me homicidal) but I won't seriously begrudge anyone for ditching the bike over winter, regardless of the benefits for your riding skill (not having the few months lay off and improving skid control).
Oh and Jimmy, get yourself a can of ACF 50 and a bottle of scottoiler FS365.
Spray everywhere but the brakes, discs and tyres with ACF 50. Get it into the electrical connectors too.
When you've been out for a long ride, spray the hot bits with the FS365. This is water based and will mist up, getting into the places you've not been able to get the ACF50.