It's true that memes have a life of their own but they are currently fueled by social media companies that operate on advertising revenue. This is a fixable problem but it requires changing the model that generates meme worthy content. As long as publishing every thought is "free" there is no viable solution to stopping meme activism because advertisers like it when people scream and shout at each other because it keeps them on sites like Twitter and Facebook longer than they would stay there otherwise. And since they stay longer because they're angry it is easier to show them ads for some product that will cure them of their ills. Commercial interests are fundamentally the root cause of this problem.