While Haskell does have customizable infix operators which can be overused and abused, that line isn't a good example of the problem in my opinion. The three infix operators there ($, <$>, and <*>) are all extremely common in Haskell code and are built-in to the language.

Every competent Haskell programmer will be intimately familiar with those three operators.

The problem arises when new libraries introduce new infix operators. I find this highly annoying and almost always consider it a code-smell. So honestly we're in agreement in general, just not with that particular example. I consider those to be basically the "arithmetic operations" of function application. Considering the entire language is based on function composition and application, I don't think it's a bad thing for an economical notation to be used.