The OED is usually a definitive definition most, even those with limited educations, can agree to accept.
I think the key here is to accept that some pipe smokers only smoke a bowl or two, now and then, rarely is ever and consider themselves hobbyists. I have no problem with "self-defining" as a hobbyist or ... dilettante . . .dabbler . . . disinterested bystander. I do have a problem when a person, I unknown to them, them unknown to me, happily and ignorantly slaps a label on on me. I'll corrent them the first time and, usually ignor them if they continue to insist. The first time is a simple, social error. The second time I consider a social, intentional slur intended to elicit a response from me.