Well, they should not have given him such a job title then.
Why is it wrong to annul the designation?
Swartz contributed technology (web.py) that Reddit used briefly, and deserves as much credit as other technology contributors of the same scale.
Founder, not sure, but your narrative of someone barely involved doesn't stack up either.
Also, early on, it seems he brought the technical knowhow, acting as an outside CTO, and also had high PR / name recognition value, so I think they owed him some recognition for sure.