There's a difference between (a) doing some language design work in private and (b) doing an entire language spec, as well as all the implementation, in secret, then one day shipping it to users and telling everyone else "here's how it is, now standardize this".

I'd also argue that languages on the Web should be held to a different standard than general-purpose languages, since there are five primary players and the Web as a whole will be worse off if some of the browsers refuse to implement what other browsers are pushing.