Why aren't there functions such as filter, take-while, etc. "by default"?

[Deniz Dogan]

Why does it have to be so hard to write Emacs Lisp without requiring cl?

Why aren't there functions such as filter (the equivalent of
remove-if-not in cl-seq.el), take-while, reduce etc. "native" in
Emacs?

-- 
Deniz Dogan