There are two types of fan arguments I assume are highly-personal issues being worked out in public generalities:

• When people get very insistent that well-regarded Western-developed shows (Avatar, Castlevania) should be classified as anime
• When people get very aggressive about what qualifies as "retro," usually accompanied by "YOU ARE NOW OLD" memes (yes? what do you want me to do about it?)

In the first case, I think it's some weirdly-derived inferiority complex involving being from a Western society yet having so much of their formative entertainment produced in Japan. I don't see why this is a problem at all—maybe, in the case of fans from the U.S., they're so used to life in the culturally-dominant society that having some of their entertainment not be produced domestically feels wrong to them, and something that has to be corrected; maybe, like the Western devs driven to take over traditionally-Japanese franchises, they feel they have to (or, at least, their society has to) produce the Exact Same Stuff as, or replacements for, the Japanese stuff they loved in childhood in order to have "made it" as creators and prove they're just as good—a sort of parental complex, with Japanese creators as the parents whose approval must be gained or who must be replaced. In any event: I skew toward reserving "anime" for stuff produced in Japan, but I'm not sure why it matters. If a show's good, it's good, regardless of origin.

The second, I think, is a plain age crisis. The people in question feel uncomfortable about seeing games they played at certain life milestones getting into double digits and what that means for their own age, and they think, like Shiori from the Utena movie, that if they make enough people feel bad about the same thing, that they won't feel bad, or at least will feel distracted from feeling bad by trying to spread hate and misery, or something. I can see both sides of the source argument here: that, obviously, consoles once new will eventually be outdated as time inevitably passes; and that "retro," in some gaming circles, refers to a certain style or styles of games identified with the consoles and arcades of the early '80s and '90s, and that the "anything older than ten years" label is kind of uselessly broad.

Hmmm. Guess that's three sides. Time for a distraction in the form of a timely gif: