"It depends". My long pipelines were still usually nice to read because I had context-relevant names and I didn't tend to name them with single letters. You could still read off from them what they were doing. However honesty compels me to admit that by Haskell standards I tended to write long variable names. Not everywhere; there's a lot of "f" in Haskell for "functions that I only know about them that they are funcitons" for the same reason one you aren't winning in C by insisting that every for loop has to use a descriptive variable rather than "i". But I tended towards the longer.

In real code I probably would have named it, but example code is always silly.