I'm gonna go use JavaScript, then.

Instead, they introduced generics, right, which is this huge, massive, category-theoretic type system that they brought in, where you have to under[stand] – to actually use it you have to know the difference between covariant and contravariant return [and argument] types, and you have to understand why every single mathematical... [I tail off in strangled frustration...]

And then what happens on mailing lists is users say: "So I'm trying to do X." And they say: "WELL, for the following category-theoretic reasons ...there's no way to do it." And they go: "Oh! Oh. Then I'm gonna go use JavaScript, then." Right?

Who in the world uses JavaScript nowadays, you morons?
I want to ask them, "do you REALLY want to go use JavaScript?"
I want to interrogate them. I want to interrogate them for roughly an hour.
Are you sure you don't just want to try saying "JavaScript"?
Coming from a dynamic language veteran such as myself, the latest trend among us vets is this, LuaJIT.
That's right, LuaJIT. This is the vet's way of programming.
LuaJIT uses trace compiling to avoid redundant table lookups. But on the other hand the cache coherency is a tad lower. This is the key.
And then, it's fast. This is unbeatable.
However, if you use heavy polymorphism then there is danger that you'll trip the guard and bail a lot; it's a double-edged sword.
I can't recommend it to amateurs.
What this all really means, though, is that you, >>1, should just stick with LISP.