I think the success of Node.js is similar to why JSON was successful compared to XML. It made some things fairly simple and easy. JavaScript is an often derided language, but it is powerful because it is native to browsers. As an embedded developer often working in C it is a welcome alternative in my opinion and I believe part of its bad reputation comes with its success.
I do indeed implement some smaller things in Node.js. Sure, the CPU and memory impact is considerably worse than most alternatives. But you also have to look at expectations towards developers. Did you have any recent clients complaining about the memory usage? IT does sometimes but otherwise customers are happy because the solution is quickly available.
When my work started to demand more code to be written outside of the browser, node was the perfect transition, because I was already comfortable with JS. I was able to achieve a lot with node & bash in terms of automation. Eventually I decided to leave my comfort zone and really learn python and I haven't looked back since. I find writing python much more intuitive compared to js, and I stick to js inside the browser.
I do indeed implement some smaller things in Node.js. Sure, the CPU and memory impact is considerably worse than most alternatives. But you also have to look at expectations towards developers. Did you have any recent clients complaining about the memory usage? IT does sometimes but otherwise customers are happy because the solution is quickly available.