I do not mean the "debauch of indices" discussed at Debauches of indices: Translation request
I have a memory of someone talking about a "plague" of indices, or perhaps of tensors. Maybe I am just confusing it with the "gruppenpest," the image of group theory as a plague on physics, but I don't think I am.
Gerald Edgar shows Dwight Neuenschwander used the phrase in a 2014 book on tensors but I suspect he got it from someone earlier. I believe I heard it much earlier than that, and since I have read Neuenschwander's book on Noether's conservation theorem I would have remembered if was associated with him. Sadly he passed away last spring and I cannot ask him.