Well, an "essay writing service" is a thinly veiled cheating service. It's intention is to assist students to submit essays they did not right.
Look up the other keywords. It's clear they want to target students.
And that's where I really think you're missing the point. If I needed someone to write copy for my website, I'd search using those same terms (and have in the past).
UpWork is a service that sells workers. You're equating essay with education, which I think is a false correlation. The reason schools pound on essay writing so much is because so many professions require competent writers. I'm an engineer and probably spend 25% of my year writing documents, essays, proposals, blog posts, and website copy. UpWork may be unethical, but Keyword-Targeting Advertisements is not a good indicator of that.
As an example, would "business plan writing" be a bad service to offer? What if an unscrupulous MBA student paid to have someone write a business plan for a college class?
I think this is mostly a non-issue and it seems like you have a bone to pick with upwork. What's the real story? Why do you hate them?