It seems the author is specifically talking about ORMs. I have not used them in Node.js so maybe they are immature. Saying "don't use Node.js ORMs" is very different to "don't use Node.js with relational DBs". The former may be correct, but the latter certainly is not.
Do not forget that the raw speed of the V8 (not to mention C++ modules for more speedup) outperforms other current scripting languages like ruby.