Well, yes, actually I would. I think the real question is why would you even want to say you were a soccer fan if your only engagement was with the World Cup final every four years? I don't claim to be a football (the American sort) fan, and I watch football matches more often than that. (Speaking of, Geaux Tigers.)
You could, do you watch football out of obligation, or because you like watching it. I'd say if you like watching football you're a fan of the game. You might not be particularly attached to the Buffalo Bills or the New England Patriots or the Dallas Cowboys or the Local Sports Team Piggers, but you have an attachment to the game itself.
I will say I'm a wrestling fan, not the WWE kind (not that there is anything wrong with liking the WWE) but rather the freestyle and Roman-Greco kind at the Olympics. I have no idea what the world standings are for the heavy weight categories, but I make it a point to watch it during the Olympics. I go out of my way to find when it's aired and watch. I don't particularly care who wins, but I want to watch because I enjoy the sport.
Well, yes, actually I would. And I would cite the fact that you don't know whether or not that is a thing as proof of the fact. The real question is why would want to say that you were a fan of my favorite team if that was your only engagement with the team? Why couldn't you just be honest and admit that you weren't a fan (that is to say, a fanatic, because that is what 'fan' means)? Why do you need to be dishonest with yourself and with me and misrepresent yourself as a fan?
In the hypothetical, given that I don't actually watch sports very often (last event I watched was the Tour de France, and my wife and I decided we were Julian Alaphilippe fans, I'd never heard of him before), I can be a fan of soccer and only watch the World Cup and cheer for my national team. Maybe that's all I like about soccer, watching my national team compete at the highest level, that doesn't mean I'm not a fan of the game, I just don't engage with it in the way that you do with Columbus and the MLS, or a lot of people do with Manchester United.
I'm not being dishonest if I say I'm a fan of something. Lets keep our Crew example going. If I occassionally listen to the game on the radio but I'm excited when Columbus wins and disappointed when they lose I would suggest that makes me a fan. If I'm listening because I like soccer and that's the only live feed I can get, then I'm a fan of soccer if not specifically the team involved.
Why doesn't it? Why would you have an emotional need to identify yourself as a fan and claim your fandom is valid if you barely cared about the thing you were pretending to care deeply about? Couldn't you at least qualify your claim by saying, "I'm only casual fan." or "Actually, I haven't really paid much attention to the team." or "I'm not much of a fan." or "I'm not nearly the fan you are." or whatever.
The better question is how does it hurt you? Why does it matter to you how I identify myself? What exactly would the problem be with engaging with a fandom in only a small way, and why would I need to qualify that to you? Why should I? Who are you to judge whether I'm worthy of being a fan, or should be able to call myself one?
In the long run the answer to all of those is none, and you're not. But again, that's me saying I'm fan. I'm not trying to join your club, merely identify that I like the same thing you do. So, if I like the same thing you do, why do I have to engage with it in the same way, or as frequently as you do?
From the perspective of the team they'll happily accept my $1 as much as your $1000, and they'll happily call me a fan. Why? Because they know by acknowledging my level of interest giving me a means to participate they can extract my $1 but it takes effort on their part to do it, while it takes much less for you to part with $1000 to participate given your level of attachment to your favourite team.
You see here is the problem - why is it wrong to say, "You're fake fan of the Columbus Crew, unless relevant stats for all of the players for the last however many years."? This is why it is such an utterly craptastic way to talk about the actual problem through this weird word "gatekeeping". The real issue isn't whether the club has standards. Isn't the real issue something like, "No girls allowed!" or something like that, and that rather than honestly admitting that is the standard, people have hid their crappy opinions behind, "You aren't a real nerd unless you can quote verbatim from the monster manual?" The real problem with a community isn't that it has minimum standards. The real problem with a community is if it is sexist, or racist, or whatever.
Yes, a big problem is that asshats hide behind "You must know X facts about Y things before you can join" when they really mean "No Homers!" (they're allowed one, no Homer
-S!). It doesn't change the fact the people that do this would do it to anybody that doesn't fit their preconceived notion of what a fan of their chosen fandom looks or behaves like. Morrus' post was making it clear that saying folks that Critical Roll and streaming shows can't be real fans of D&D isn't allowed around these parts. The reason Morrus has unfortunately had to point this out is that there are some people that claim CR viewers (lets assume some portion of them don't play the D&D TTRPG) can't be real fans is because they don't know anything about Mystara, or Greyhawk, or Blackmoor, or whatever. I think you'll agree that's dumb.
If somebody wanted to join a D&D game then that group is well within their rights to set whatever rules and requirements you want. You could make them filling a 1000 question quiz to determine if they're going to join, that's up to you. However, nobody gets to decide if I'm a fan of D&D, or the Columbus Crew, or Local Town Sports Piggers but me.
You can still be a douche without be sexist, racist or whatever. Mind you those are views that tend to get held by certain people that want to be gatekeepers Particularly with D&D. You're right in saying the problem isn't that D&D has minimum standards to be a fan, it has 0 standards to be a fan of D&D; rather the problem is there are some people out there that think it should have minimum standards, and act like they know for certain what those standards are and will enforce them.
Gatekeeping isn't a weird word, it has sociological contexts that are being used accurately to describe the particular behaviour Morrus wants to stop. The reason he wants to stop that is because D&D fandom isn't an exclusive club or group, its an open ended concept that changes and morphs over time. You can join or leave as you wish, there are no specific rules that must be followed. I think the only general concept is you have to like D&D in some capacity.