a_sane_person

Oh for crying out loud, can we not do this for once?

No one, literally no one, using the incredibly common idiom of "dead in a ditch" is thinking of or referencing anything to do with Native Americans, alcohol or this person you've just referenced who I've never heard of before.

There is roughly a 0% chance that someone saying that phrase means it, or has ever even heard of it as, the weird imaginary negative stereotype usage you've claiming here.