Yeah, makes sense it sounds like that. But the crux is probably that most of us learned programming via Algol-like languages, like C or PHP, and only after decades of programming did we start looking into lisps.
But don't take my word for it, ask the programmers around you for the ones who've been looking into lisps and ask them how they feel about it.
I don’t think that would be a real issue in practice. Coding LLMs need to be able to cope with complicated expressions in many languages. If they can produce legitimate code for other languages, they can be taught to cope with s-expressions.
> shame LLMs struggle
That sounds like Stockholm syndrome more than an easy-to-use language.