Because it used to be "free". People don't value that much their private data nor ads-free web. I always say to my friends that "if the product is free, then you are the product". They understand that fact, they just don't care - and why would they?

I would pay .02$ for displaying a news page (it's is still 4 times more than what advertisers give to publishers) and probably everyone would - but disrupting trillion ad business is not that easy.