One of the core tenets of human psychology is that anything anyone does is done for a reason, even if they're not cognizant of what that reason is.
>soiposters
These people actually resonate with the soi man on a personal level. They don't use it to make fun of anyone, as the meme was originally intended, but because they see the soi man in themselves. It's a self-deprecating projection of their own self-image onto other posters, which everyone does, and in the case of soiposters they project their own effeminacy, emotional incontinence, and unattractiveness (the connotations of the soi man) onto others via soiposting.
>frogposters
These people are generally low IQ, and as such are unable to communicate with others very well verbally. Due to this, they feel lonely and isolated, and are searching for a sense of community, with low social risk (anonymously, so as to feel comfortable and not experience the pain of social rejection as strongly). So they post frogs as a kind of infantile call & response mechanism, to say "you hear me, right? I exist, right?" -- this kind of searching for validation. It's similar to a game of catch, where nothing of value is achieved but it's a better way to pass the time than doing nothing at all.
Unfortunately, both of these posters have a significant net negative impact on the board, since instead of making good-faith attempts to exchange information they are simply externalizing their personal inadequacies, whether they are aware of them or not.
>what should such posters do?
Cultivate a sense of excitement in arriving at the truth, and curiosity about the knowledge of other posters. Usage of these memes is toxic & traumatic and hinders network consensus, since it is effectively spam. Posting frogs and soimen in a bid to get a reaction out of others is not only degrading to the board, but degrading to oneself.