Credit to Colin Webster, son of NFL hall of famer Mike Webster, this is me paraphrasing something that he used to have online :
There was more to the terrible towel than a marketing gimic.
… … …
The terrible towel originated in the Steelers weight room from a finisher akin to Mas wrestling.
The players feet to feet and holding onto (eventually) as many as three towels as (picture a couple of very strong heavyweight lineman) players were ripping the towels during the “terrible towel” drill.
Frankly I’m unsure as to why they didn’t just use a sturdy stick, pipe, or length of rope.
Towels were on hand.
Towels it was.
Eventually the towels made their way into the seating.