Citation needed.
Python is a popular first / teaching language and it has as many (and probably much more in 3.5) features as JS.
And Scheme is supposedly simple, but not that popular with any large amounts of people, beginners included.
There are features that interact in mysterious ways and can be difficult to master (C++ has a lot), and features that are mostly orthogonal (e.g. template strings don't complicate anything related to arrow functions and vice versa).
What I'd like to see, with regards to Javascript, is for "strict mode" to extend to the correction of old, long standing warts (e.g. crazy coercion rules etc). But I guess with this new shared "bytecode" for the web announced, we probably wont have this problem for long.