Umm ianal but isn't saying all publishers don't get paid the opposite of discrimination?
If they said some American companies get paid but not french etc I would totally get it.
A way of seeing this is that it might be fine for the big players for national and international news (Le monde, Le figaro ...) , but probably has a much bigger impact on small news outlet, because if they dont agree they are at a disadvatage obviously, so they cannot afford to say no, but at the same time they might already be in a difficult financial position, and that revenu might have helped.
The key part is that google had no real justification according to the court to treat everyone the same way, and that consitutes discrimination.
It seems a bit weird to me too but you could make a parallel to a school that has a set meal price for every student, regardless of parent income.This would obviously be discriminating towards the poorer students.
Now whether google is a public service the way school lunches are is up for debate but i think it basically comes down to equality vs equity
And my suspicion is that the value to Google is likely inversely proportional to the size of the news source, and I think the smaller publishers are hurting the most. I care to some degree that the NYT shows up in Google (but not much, really) whereas I couldn't care in the least about whether a local news paper in West Virginia is indexed.