Certain activities attract certain stereotypes of people. For instance, the main demographic of fishermen tend to be older men who happen to reside in more rural areas. This is not an accident, but rather on purpose. To be able to fish, you require adequate strength, possess the ability to drive yourself, the willingness to be cut and injured, and to be near water which can support wildlife, not something you usually find in large cities. The requirements for participating in this activity select the participants of that activity, as for those individuals the activity has less friction than other activities. It would be difficult to get into fishing if you lived in the Mojave Desert.
I think that the amount of friction preventing or allowing an individual from performing an action drastically affects the likelihood of that action being taken by the individual. Take two people - Alice and Bob. Alice has no tools in her kitchen, while Bob has a fully stocked fridge and all the tools he needs. Bob will be more likely to cook dinner than Alice given all other factors are relatively equal. For Bob, cooking dinner is a simple task as his environment has been set up for less friction for him to cook. However, for Alice, she would have to make trips to the supermarket to purchase tools. The additional mental effort of preparing introduces friction between Alice and her kitchen, making her less likely to use it as much as Bob.
In a sense, the anime community is the same way. The friction of joining the anime community has degraded to a certain point at which anyone can just get into it. It’s never been an easier time to be an anime fan and to be involved in the anime community. Anyone can do it.
And therein lies the issue, that anyone can do it. If there are too many fishermen on a pier, the lines get tangled up. When you cast, you have to worry about hitting people with the line. The pier bans overhead casting and forces participants to underhand cast only. The fish cleaning stations form lines, while the fish rot. The high barrier to entry of fishing ensures the level of participants be enough to ensure each participant is able to enjoy themselves and not have issues doing what they enjoy. The gate is kept by the size of the pier, the dangers of cliff fishing, the price of fishing gear, the parking in the area, and other physical factors that prevent the sport from being too crowded.
Online spaces do not have these physical limitations. There are no limits on how many people can enter. You can’t go to Anitwitter and immediately see that the pier is crowded. But it is, and the impacts can be felt. When the field is so crowded, the most vocal and ideologically aggressive dominate the conversation, and everyone else is kicked out of the deep end of the pier to the shallows. Yet, the most vocal have nothing to contribute, so they converse with each other.
This is the lowest common denominator. Online anime culture spaces, due to their own popularity, ease of access, and lack of gatekeeping, have filled themselves with the lowest common denominator, whose ideology takes over as the dominant thought within the space.
While online spaces do not have physical limitations and can scale to as much as technology will allow, there is a limit to the amount of exposure each single participant in the space can get. Each person can only consume as much media as their time allows. If they permit themselves to consume and propagate content from the lowest common denominator, they will understand nothing but the lowest common denominator. Those who have isolated themselves from this ideology will move to other piers, or take up other sports such as hiking or golf, as the friction from entering the space will have increased due to difference between their perception of the hobby versus the image of the hobby shouted from the lowest common denominator.