I'm not against creating new languages. In fact the Lobster language is something I would want (although current syntax is bit repulsive). Python with static types but without getting in the way is pure gold. The problem is that creating interpreter/compiler is one tiny little part of creating language. Much bigger task is creating vast number of libraries that every other popular languages have. Think about everything from numpy to scipy to graphics to networking to web frameworks to OS APIs... Another bigger part is creating tooling and interoperatibility - everything from debugger, refactoring, linting, IDEs, CI, docgen etc. Now put on the top of it all the reusable code that millions of people have already written spending billions of hours in existing languages.

Without large teams working for years, its very hard for a new languages to break in to general use. There are ofcourse outliers and you can get lucky - but then you have to be terribly lucky. So the end result is that 99.9% of languages just die or become hobby project for a person regardless of their features, benefits, beauty or aesthetics. Again, nothing wrong with becoming personal hobby project but if my goal was to create game engines that becomes force in the industry, I would probably not start by creating entirely new language.

I'm not experienced as much as the author, so this is my personal opinion and likely not very well informed. I writing this just because I see several people spending years in creating new languages while their goals have been something else. They dream about repeating success of Java while not realizing how rare it is. After they finish their labor of love, I wonder if they find it depressing to become just line item in the list of dead programming languages. What if they would have actually focused on their original goal instead with emphasis on adding new powerful features that integrates and plays well with existing stuff? It's sure not as sexy and respectable as being father (or mother) of new language but has much higher chance of generating desired impact.