I think it's more a lack of integration: None of the graphical tools integrate well with the programmers existing editors, vcs or anything else very well. The

I think it's more a lack of integration: None of the graphical tools integrate well with the programmers existing editors, vcs or anything else very well. They need to be represented by a textual format, carefully planned so that it is easy to manipulate in an ordinary editor with understandable diffs in version control.