They could any time they wanted to, googlebot respects robots.txt prohibitions. They want google to direct traffic to their websites and they want google to pay for the privilege...
I feel like this is the weakest take on the argument.
They want google to pay for re-hosting /lifting any content (previews, headlines, etc.). Linking is just caught in the crossfire, if it's even mentioned.
If we are being honest, the majority of people read headlines and don't bother with more than the first paragraph or summary of the article. This is all displayed on Google properties where users don't even leave the Google infrastructure.
Is Google providing a service? Definitely. Does online news depend on Google? Definitely. Is Google's relationship with them abusive? Definitely.
