What counts as a legit criticism? So much of our field is taste-driven. And so much criticism was aimed at old iterations of something, gets carried on in flamewars, but no longer applies to the latest version (e.g. "Java is slow").
All the JS-the-language criticisms apply, those are probably the biggest at this point. The classic "node.js is cancer" is still somewhat relevant though I never thought it made its point well enough on how forced-asynchronous is at least as bad as the forced OOP and checked exceptions we put up with in e.g. Java again. Callback hell was long a common complaint, until people found Promises / the waterfall structure, but then the complaint is debugging hell. The new await stuff in node 8 sounds nice at least.
For a long time npm didn't get stuff over https by default, I think it does for a year now? The only other criticisms I can think of are just shoddy engineering that turns into drama (I remember seeing something about their colorized output would slow everything down quite a lot) or more taste-level things like how seemingly trivial concepts like leftpad are core libraries (that go through multiple versions because it couldn't have just been done right the first time) and the drama involved when something everyone depends on has an issue.
Disclaimer, I haven't done production node since ~2013. It was actually mostly enjoyable, and I wouldn't mind doing it again, despite on the taste-level I think the whole node ecosystem is just worse than many other options (when you have a choice) for many specific problems. But life is a continuous lesson in Worse is Better.
All the JS-the-language criticisms apply, those are probably the biggest at this point. The classic "node.js is cancer" is still somewhat relevant though I never thought it made its point well enough on how forced-asynchronous is at least as bad as the forced OOP and checked exceptions we put up with in e.g. Java again. Callback hell was long a common complaint, until people found Promises / the waterfall structure, but then the complaint is debugging hell. The new await stuff in node 8 sounds nice at least.
For a long time npm didn't get stuff over https by default, I think it does for a year now? The only other criticisms I can think of are just shoddy engineering that turns into drama (I remember seeing something about their colorized output would slow everything down quite a lot) or more taste-level things like how seemingly trivial concepts like leftpad are core libraries (that go through multiple versions because it couldn't have just been done right the first time) and the drama involved when something everyone depends on has an issue.
Disclaimer, I haven't done production node since ~2013. It was actually mostly enjoyable, and I wouldn't mind doing it again, despite on the taste-level I think the whole node ecosystem is just worse than many other options (when you have a choice) for many specific problems. But life is a continuous lesson in Worse is Better.