JavaScript is a scripting language. So is Python and Ruby. As a scripting language, excluding all bindings (files, networking, etc), JavaScript is substantially faster than Ruby or Python.

Now, in terms of bindings, bindings to libuv are also fast. So node is not so much of a problem in itself.

However the problem is how the language is being used:

To say you can write a serious library or server code because you know JavaScript, is the same as saying you can write a paper in cardiology research because you know English.

You will find a lot of people that completely disregard the domain knowledge required to write safe, workable code. While this happens in many languages, JavaScript is the lingua franca for those kind of people.

Because of this, be very careful of the libraries you use. You will most likely have to read the code to ensure there is some thought behind it.

Then if you are hiring node developers, prepare to receive an avalanche of resumes from people without a degree expecting to learn on the job at your expense while receiving a 6 figure salary.