Your critique is off the mark. IDE can do things that make no sense as a language feature but help you write code very fast. Command keys for things like show me all senders of this method, show me all references to this class, show me all implementations of this method, show me all inheritors of this method, go to the definition of this thing, show me a tree of the class hierarchy, rename this method fixing all senders, extract this code into a new method, extract these methods into a new superclass, push these methods up or down in the hierarchy.

These are things IDE's can do for you to enable you to code much faster by being aware of the structure of the language rather than editing everything as streams of text. I work in sublime text 2 doing ruby code, and I miss the hell out of these Smalltalk IDE features, text editors just can't compare; they're great at slinging text, but I don't want to sling text, I want to sling around semantically relevant chunks of code in ways that don't break it automatically.

These days, the IDE is apart of the language; we will see more languages that push integration with their IDE in as much as Smalltalk did in the past.

No one would think about using a language without a compiler, developers increasingly feel the same way about the IDE.