The A.V. Club
I'm a porno-dealing monster! What do I care what you think?

It's backed up by the fact that the first recorded versions are found in 19th-century America, which wasn't particularly plague-ridden, and a lot of the early versions don't include the bits used as evidence for the plague interpretation anyway (plus those bits don't actually describe plague symptoms that well).

The version I learned (from my dad, so thanks for the childhood trauma, Dad) concluded with "French-fried eyeballs cookin' in a
pool of blood," a line which I haven't actually seen in any of the
versions recorded on the internet, and which I always found unbelievably horrific.