Sure, your word was "just". I'm not sure what nuance I missed in "It's just that Javascript will need to catch up with core language tools for another decade"

Sure, your word was "just". I'm not sure what nuance I missed in "It's just that Javascript will need to catch up with core language tools for another decade" such that "It's only that..." would not work. (Anyway, I would agree with what I think is your actual position that it's more than just language tools; not arguing...).