I disagree on everything you said about scala, except your point about JVM :) but obviously I am biased. WRT to JVM, pure FP recursion (beyond simple tail call

I disagree on everything you said about scala, except your point about JVM :) but obviously I am biased. WRT to JVM, pure FP recursion (beyond simple tail call elimination) relies on trampolining which is a whole other can of worms. Stacksafe but with heavy performance penalties.