I don't see how prefix notation would ameliorate this problem. You'll still wind up with:

    (+ ( ... big thing 1 ...)
       ( ... big thing 2 ...))

I don't think this syntax does a better job of conveying a lack of ordering between the two things. I'm inclined to argue that it's worse simply because Lisp is sequential and the math you did in school wasn't, so you have experience looking at the bigger picture with infix versus prefix. But both of us are bullshitting, because we haven't got any science to support one position or attack the other, only reasonable-seeming hypotheses.

Haskell is my favorite language, but I find I get a lot more use out of converting words to operators than converting operators to "words." For example, I find this:

    x `elem` y

a lot more intuitive than:

    elem x y

because the infix version suggests the natural English reading, that the set is the second argument and the item is the first, where in the prefix case I have to think about it for a second.