It's because the best language is the most ubiquitous one.

You can paper over syntactic annoyances and semantic confusion with a mental mind-shift, and once they do, they become barriers to entry for your competitors. You can't paper over an inability to deploy your software in front of a customer. From the POV of "what's a showstopper, vs. what's an annoyance", ubiquity is the most important feature a language can have.