A serious problem with Node was the callback pyramid of doom.
This means deeply nested callbacks such that the indentation wanders steeply to the right. When you do loops or have exceptions programming got very confusing. In effect you have to do a continuation passing transform. It's not difficult but the results are utterly unreadable. For example a simple for loop could be transformed into recursive function because this way it is easier to keep state between callbacks. It's a nightmare.
What I found surprising in the early years of Node that some people in the mailing list had a «Real programmers don't use Pascal» attitude.
Bruno Jouhier's developed streamline to simplify and automate the continuation passing transform. One could almost program in a «blocking» style. I found his work really amazing. However for that Bruno got attacked in the mailing list.
Then Marcel Laverdet developed fibers. A different and equivalent way to solve the callback pyramid are fibers, coroutines and generators. This way we don't need the continuation passing transform. But the reception in the mailing list was at best only lukewarm. Anyway, the developers of Meteor saw the potential and decided to base the server side of the platform on fibers.
And now JavaScript has generators and async/await. And lo and behold: with these official solutions the hard core programmers swayed and accepted «Pascal».
In my opinion, Ryan Dahl has missed an opportunity. Node was by large not ready and finished when he left. He should have tried to convince the community to find a solution for the callback hell.
I think I understand people like him. They are always on the lookout for fresh ideas.