Haters gonna hate, but well-written JS performs better than most php software.
You could argue Javascript makes it easier to develop shitty code, but if you look at java, C and any other language for that matter, most software is shit and the one to blame is the programmer, not the language.
From shit ass slow angular websites to instant loading react ones, there just can't be a generalization. You have awesome software like Atom written in node and I bet many people would never realize it was written with Node.js.
We also have a lot of proprietary crap (look at IBM/MS stuff) written in C and now Java which are slow as a turtle. Node by itself is a fine tool and it sure does help me build better websites.
Just don't think a MEAN platform is gonna be the best for everything. I've often used node with PostgreSQL, for example, because it was a better combination for the job. The same applies for LAMP, it's not snake oil. Know your tools and use them wisely and you'll be fine with whatever path you pick.