On Tue, Oct 6, 2015 at 8:18 PM, Richard Stallman <rms@gnu.org> wrote:
Emacs with GUD is an IDE.

Wow Richard!  I get that you probably have never used an IDE.  Have you ever had one demo-ed for you?  Please assure me that your grasp of modern IDE functionality extends beyond what that statement suggests.  I can never recall a time when anyone working in the tools and development environment areas would have concurred that Emacs+GUD constitutes an IDE.
 
It has a big advantage compared with other IDEs:
when you see a source file, you're editing it with Emacs.

To what are you contrasting Emacs+GUD?  GDB with only a command-line interface?  GDB with TUI?  For decades source display integrated with visual indications of the locations of breakpoints, and highlighting the current execution line has been the absolute minimum ante for debugging support within an IDE.

If it falls short compared with other IDEs, I think this would be a
great area for improvement of Emacs.

I use GUD + gdb-many-windows.  I put up with its quirks, shortcoming and idiosyncrasies because I am an old geezer devoted to emacs.  And I would love to see an improved debugging environment.  But no amount of improvement along those lines will give Emacs any stronger claim to being an IDE.

/john