The same problems you cite for node.js are the reasons why a lot of devs love node.js.
Its much easier to do your own research and find the best module to solve a particular problem you are having then to shoehorn into some larger monolithic framework.
Also its a lot more fundamental then that - Node.js has prolly the fastest iteration cycle for any platform out there since its so easy to create your own module - it leads to some sort of Cambrian explosion of innovation and experimentation.
EDIT:
Also OP seems to think callback hell and async programming is bad. The important thing is those things are problems for python/.... too !
Its just that python doesn't have a good programming model to even begin to address those concerns.
JavaScript at-least tries to say - "hey this is a problem we need to deal with - concurrency is a issues we all face "
So when devs complain about callback hell - its just that they have never tried to use python to do async in a neat way.