To get any programming done, you
have to learn certain things, you can't complain that it takes weeks to learn a new programming language and months to assimilate it's model of thinking.
But saying "you need to spend a few months to get intimately acquainted with the language" is just not going to work in practice if you're hoping about breaking in to the mainstream.
You mean it's okay for everyone to struggle to work with JavaScript for years and years trying to come up with an OO system and a module system and trying to just bundle the files for the browser, but it's not okay to spend months on getting intimately acquainted with the language?
Who cares if Rust becomes mainstream, we only need the best open source code to use it (like Firefox and the other C/C++ libs that are thinking of porting over). We don't need it to be mainstream, we just need it to be possible to learn it within a reasonable timeframe (less than a year).