FWIW I think "2-Place and 1-Place Words" is a bit dubious for similar reasons. Both this post and that make the crucial observation that we have this confusing concept that looks like it's a good concept "partially applied", but use this to diagnose the problem as incorrect usage of a concept, rather than viewing it as a perhaps historical account of how that confused concept came about.

What do you mean by an incorrect use of a concept? If you curry a function, you get a new function, in this case a new concept that happens to be confused because the original function needs all 3 places to make sense. It says so right here in this post. I'm inclined to believe the disagreement you posit simply doesn't exist.

Would the historical account be that it was a less of a hassle to drop the agent from used language, and over time some people dropped it from the underlying concept, and got confused?