Your English notation is not really an S-expression. I would say it is similar in that the operation comes first. Even though people understand such notation for simple expressions, most people are not used to doing advanced (beyond elementary school) math using such notation.

I agree that the concepts behind S-expressions are simple and logical, but expressing an entire program using S-expressions is an additional thing that must be learned. Other languages chose a syntax that is closer to what people are used to and that helps with the adoption of the language, even if the language loses other capabilities.

Yes, that right. And moreover, much math isn't infix: Factorial is postfix. Sum, Product, and Integral are prefix. Infix is actually the exception, and is not semantically uniquely without parens anyway (languages have different orders of operation!), so folks should just get over the mindless prefix hate.