What I want to know is why will isomorphic JS work where other attempts at isomorph-isation have failed. Both the Java and .NET ecosystems have made attempts as

What I want to know is why will isomorphic JS work where other attempts at isomorph-isation have failed. Both the Java and .NET ecosystems have made attempts as this and yet their contemporary development practices for both are back to fully-segregated client and server code. Also I don't really understand the performance argument. Was that just a strawman on the part of the author?