A large number of engineers are not interested in learning JavaScript since they may be very fluent in their language of choice. I think it would be better for

A large number of engineers are not interested in learning JavaScript since they may be very fluent in their language of choice. I think it would be better for everyone if they can bring in their expertise also to the web platform. Also I don't think they are being unambitious by not wanting to learn JavaScript since all languages have many warts and learning all of the peculiarities of how to do the same thing in different languages is not going to make you a better programmer.