His point is: while these things can be nice, no one cares about them other than language designer. They are only means to an end, which is user experience. Sure, some car buyers may know or care what alloy their cylinder block is made of, but a lot don't know, and don't care, how many cylinders there are. They only care (somewhat) about how it drives. And it is certainly possible to have a language with all the theoretically nice features, but offering horrible user experience for a specific purpose. Part of it is just marketing, but part of it is also optimization with a different purpose in mind.
For example, his purpose, and Julia's main use case, is often different from that of either a language designer or a software engineer: e.g. performance and fast prototyping are first order concerns (together with a decent scientific library), and everything else, like longevity, ability of future code reuse, or simplifying work of teams are way, way down the list. The reason of course is that ~90% of code is written by one person, for himself, to effectively run once and produce one paper, and to be never touched by anyone ever again. At least, this is what I see in my field, which is largely dominated by Matlab (and Matlab-like syntax is definitely a huge asset here).