This is probably the best take. If someone says that ads are part of the deal, fair enough. I can go somewhere else, or I can honor the deal. Otherwise, seems unethical to me.
What "deal"? They are providing publicly accessible information, I'm choosing to only download a portion of it. If this is affecting their bottom-line, maybe they should rethink their business model. Not my problem.
I block ads to save myself from buying things I don't need, to save myself from being tracked over the internet, and because they are often annoying and sometimes contain malware. I see nothing wrong with this.
I'm not the one that is abusing some sort of "deal", in my opinion.
