Most people don't care about things. This is kind of a recurring problem. Imagine if people just cared a little bit more. All sorts of problems, like littering, would just go away.
But people are lazy and don't care. They don't care that their behavior today will be a problem for them tomorrow.
The big sites are where the content is, and that's what they want. Suffering a little bit of hardship (fewer memes) in order to bolster a stronger future? Ridiculous.