But anybody that writes off an IDE without fully understanding just how powerful the two features I mentioned above can be when dealing with multi-million loc codebases is being narrow minded.
Yes! This is the crux of the confusion. Working with a multi-million LOC codebase is a very different problem than a 10,000 LOC codebase. Java+IDE is better for the former; dynamic language + text editor is (usually?) better for the latter.
When people voice angry opinions about static vs dynamic languages, and IDE's vs text editors, they should preface with how many lines of code are in the typical projects they work on. It just changes your working assumptions.