For people that like functional style and using recursion for everything, TCO is a must. Otherwise there’s no way around imperative loops if you want decent performance and not having to worry about the stack limit.

Perhaps calling it an “optimization” is misleading. Certainly it makes code faster, but more importantly it’s syntax sugar to translate recursion into loops.

TCO is less of an optimization (which are typically best-effort on the part of the compiler) and more of an actual semantic change that expands the set of valid programs. It's like a new control flow construct that lives alongside `while` loops.

It virtue-signals that they're part of the hip functional crowd.

(To be fair, if you are programming functionally, it is essential. But to flat-out state that a language that doesn't support isn't "serious" is a bit rude, at best.)

functional programming background / SICP ?