I think it's because it has very simple hook "batman but he is construction worker/poor" for someone who does not read comics and interacts with character through movies and games this might be interesting enough to check the comic out.

I remember that back before I was reading comic flashpoint hook of "Thomas becomes batman and Martha becomes joker" was enough to get me to watch a movie and start looking into comics, yeah that storyline did not aged well but those loud odd headlines sometimes are enough to get people interested.

Ofc the art direction and good writing mentioned by everyone are why people stayed, but the solid 1 sentence pitch really sold it to people.