No, don’t ignore problems of TCO by saying “guys don’t like functional programimg”. Guido cleary states why he doesn’t like it: . Even though TCO is one of the ES6 standard, TCO also is largely denied by JS implementors (Firefox, Chrome, and Edge devs) because of the similar reasons. As a result, Safari is the only browser that supports TCO.  And Rust team is not eager to introduce TCO .
We will sometimes optimize for TCO, that issue is that we can’t guarantee it just yet.