I guess it really depends on what we each choose to use to define the term "biker."
I am sure to some the term biker harkens an image of the stereotypical "outlaws" of the Hells Angels so immortalized by those famous "B" movies of long ago. Some may identify with Sonny Barger and the atypical "biker" image.
I think though for the most part all stereotypes aside...."who gives a rats nest?" If you ride in all weather, wear full leathers, traditional biker boots, half gloves , and a leather jacket/vest and a doo-rag skull cap you may well be a "biker"
If you ride three days a week and only in fair weather and dont wear leather but a full coverage helmet ..does thay classify you as a casual rider?
I really dont think it matters. All that does matter perhaps is that you ride a unique bike and you endeavor to do so with some modicum of safety.
But some of us do look like gangstas with a bandana and dark glasses. My wife accused me of same yesterday. but you will not see my hangin out at the "Bashful Bandit" bar.
I just ride the doggone thing and I dont worry about the stereotypes. They aint going away as it were so you live with them or a lack of them thereof.
