I think that much of these criticism relate to the implementation, and the runtime (i.e. browser) rather than the language itself. As a scripting language for a browser environment it's pretty good. Modern variants have lots of lovely language features and tools like babel mean you can use a lot of these new features without sacrificing backward compatibility.

The threadless/nonblocking model is "interesting" but in my opinion its wholly suitable for user-oriented scripting as it forces a style of development that doesn't block.

The null/undefined thing actually makes sense to me. The concept of "Null" is a swirling vortex of uncertainty in most languages and it's nice to see it get some more nuanced treatment.

There's something about the bloody-minded pragmatism of javascript that appeals too ... it's very much a language that has evolved from the bottom up based on need, and much of it is very much community driven. You see problems solved in interesting and unusual ways that you mightn't see in a more stringently stewarded language.

I wouldn't use it for everything. I wouldn't prescribe it for beginners to programming either. But it's great for what it does. I like lots of other languages too, but I respect their applicable limitations. It's a nice language.