Hard to TL;DR because it's a twisty tale that doesn't make a lot of sense.

It was the name of an unrelated book by an obscure author that was adapted into a "film treatment" by Willam Burroughs; and it was sitting on the right shelf when Scott and Co. were scratching around for a title. Neither manuscript had an influence on the final film, and the term "Blade Runner" is never explained in the film.

Thanks. Looks like the complete answer would be something like, "There was a book about 'bladerunners', black-market couriers of medical equipment like scalpels, and they liked the name and adopted it for the unrelated film."

A wild ride of a read. What was clickbait to you?

When someone sees the headline, the natural impulse is, "I wonder why they called it Blade Runner; if I click the link, it will tell me." But ten long paragraphs into the piece, there's no sign of an answer.

I guess you had to read the whole thing? The title of "digging into the odd history" suggest that it's going to be a tale. History doesn't exist as simple quick answers.

Sure, but I think a lot of people who saw the headline were only interested in the simple, quick answer, which was certainly enough for me.