My thoughts about Javascript are that it is an easy language to pickup, flexible, and potentially dangerous to those who are inexperienced. The syntax for Javascript is fairly easy, and there are many resources out there that can help someone learn the language. Javascript is incredibly lax when it comes to variables, which is nice as it saves some time while coding. At the same time, these lax properties can also be dangerous, as a person can easily overwrite variables with different data types and pass extra parameters to a function and not have an error thrown. I did learn new things about ES6 from doing the tutorials about ES6 features. These things would be using classes in Javascript, and the deconstructing of arrays or objects using the curly braces.
From a software engineering perspective, I think Javascript is a good programming language. There is a variety of things that can be accomplished using Javascript, and it is fairly easy to learn the basics. I do think there are flaws to Javascript, but most if not all languages have their own flaws. Despite the flaws, the beginner friendliness of Javascript makes it an ideal language to start with for software engineering, and a language that can be used down the line.
As for athletic software engineering, I personally do not like it, but I understand and appreciate the idea behind it. I find the practice WODs useful for extracting vital information quickly and processing it just as fast. This allows a roadmap of what needs to be done and how the task will be done to be planned much quicker. However, the pressure of having a short time limit compounded with the aspect of being judged for the results does add a significant amount of pressure. This pressure does not detract from the joy of coding, but the pressure masks the joy most of the time, until the WOD is over. I do not think this style of coding will work for me in the long run, but it is a much appreciated experience that I believe I will not regret doing.