I could care less either way, but by definition it makes sense for someone that does it on the reg.
Hobby
1.
an activity done regularly in one's leisure time for pleasure.
"her hobbies are reading and gardening"
Then wouldn't this also apply to masturbation? "My hobby is masturbating" has a weird ring (lol) to it doesn't it?
"My hobby is eating snacks"
"My hobby is taking baths"
"My hobby is visiting my parents on the weekend"
Idk I just think there's a difference between a hobby and an activity you simply enjoy doing. Not everything is a hobby just because it's fun to do imo. If it's tied to basic needs (like food, sex, hygiene, personal relationships) I wouldn't call it a hobby, but that's just me. I don't have a monopoly on language.