They could just drop their opengraph tags if they don't want their content shared in this way. Of course, a simple link will be much less appealing to click on for most users.
Much less appealing to even read in the first place. Plus you're also in competition with other publishers who will happily gobble up the impressions you used to take. So even if you're willing to play hardball as a publisher, you don't have any real capacity to coerce the social media company.
It's this imbalance in bargaining power that the Australian law at least aims to change (and it's why it's administered by the competition and consumer commission).
Seems like the real problem is "competition with other publishers who will happily gobble up the impressions", and the goal of the law is to reduce such competition?
I hate Facebook, but I think laws to reduce competition are pretty stupid and do not benefit public.
It's this imbalance in bargaining power that the Australian law at least aims to change (and it's why it's administered by the competition and consumer commission).