I have not found the cultural climate on HN to be opposed to the GDPR at all. Both its goals and its implementation seem to be popular here overall, and most comments I see that are critical of it get enough downvotes to have their text significantly desaturated even if they're making a good argument.
It's my impression, though I have not worked in the field that people operating ad networks believe some kind of tracking is necessary to prevent click fraud, and do not want to sell ads free of any tracking even when they have customers asking for the option. I don't know how true this claim is or whether alternatives have been adequately explored.
What I do know is that some of the industries that use ads, such as newspapers are struggling to make enough money to continue operating. Nobody will miss a scummy adtech firm, but people might miss local news outlets. It's valid to talk about the impact on business not just in terms of profits, but also considering potential positive externalities of the continued operation of a given business.