What I'm saying is that the term "hobby" and "hobbyist" apply only if YOU want them to apply; in general terms, anything we do that does not involve monetary gain can NOT simply be called a hobby. And, of course, anyone using a certain item (technological or not), is not a hobbyist just because that object is not productive, i.e., a computer that one uses for something (emailing, surfing [which I personally spell Cerfing, after Vint Cerf], solitaire, et cetera) that can easily be done on their cell phone. That person does not maintain said computer as a hobby.
In my opinion, the Amiga in NG form or not and AmigaOS 4.1 are no more a "hobby" than owning or driving a car. If YOU want it to be YOUR "hobby," then only you have that right to label it such; others cannot make a blanket statement about the usefulness of any item (or OS) just because it does not meet their definition; it only has to meet your own definition.