If I remember correctly, these packages are the straw that broke the camel's back on creating NonGNU ELPA. emacs-devel decided against adding these libraries be

If I remember correctly, these packages are the straw that broke the camel's back on creating NonGNU ELPA. emacs-devel decided against adding these libraries because they are non-idiomatic, and also because they would be polluting the namespace--I recall the emails specifically said that the s-* prefix would not be given up, as it is such a convenient one letter prefix. NonGNU ELPA was created so that they can alias these packages to something else, and keep using them as dependencies, without giving up the prefixes f-* and s-*.