For me, the biggest problem is that d3 is a declarative library which you write code procedurally for. If you look at d3 code, it has lots of imperative-style v

For me, the biggest problem is that d3 is a declarative library which you write code procedurally for. If you look at d3 code, it has lots of imperative-style verbs (enter) which are not readily clear. Quite simply, there's an impedance mismatch.