an optimized C compiler won't always write the best code in a best practice way.

Aaand, therefore, you might not suggest to people that a good way to learn to write good asm would be to study the output of a C compiler. However educational that experience might be.

Also true: no matter how good something is, there'll always be someone eager to put it down.

Not sure where this is coming from unless you think we're having a conversation about the merits of a language, instead of the merits of learning another language from the output of a transpiler.