The trope namer is Warhammer 40,000, where it is the Ork onomatopoeia for machine gun firing, and their general term for rapid fire capacity: “dakka-dakka-dakka-dakka...”.
Here’s a color version of the image on the page, that honestly conveys the heuristic to me quite effectively. It’s very stupid, but man it’s good to just go more dakka when marginal effort is continuing to improve things.
This is the canonical More Dakka post, but it doesn’t include the origin.
Quoting the TV Tropes page on More Dakka:
Here’s a color version of the image on the page, that honestly conveys the heuristic to me quite effectively. It’s very stupid, but man it’s good to just go more dakka when marginal effort is continuing to improve things.