[TeMPOraL]

'pdonis gave you the correct answer, but another way of thinking about it: because Lisp way is more consistent. It also makes it more powerful.

The math notation we commonly use is mostly a legacy notation, invented before we had computers and could do (or conceive of) symbolic processing. We write `f(foo, bar)` instead of `(f foo bar)` not because the former is better, but because it's been established before we invented trees (data structures) and figured out why they're important.