But seriously, this is almost entirely bullshit. I've used IDEs for a long time, and they just don't encourage the problems you're describing here. Bad developers do, and that's totally independent of your language or your editor. Maybe you don't have to work on million line projects but lots of people do, and maybe, just maybe, it's not their fault and maybe, just maybe, there are totally valid reasons that their projects are like that. It is my opinion that mere editor "users" (because seriously folks, many of you are the kind of people who can't get off your high horse) never understand that, and refuse to accept that perhaps other people might like different tools or work in different scenarios than they do.
And yes, I used Emacs for 8 years. You couldn't pay me enough to go back.
If your "million lines of code" project isn't well documented or designed, then relying on an IDE to find pieces of code doesn't really help.
It is also my "conspiracy theory" that because IDEs are so good at hiding the junk under the carpet, developers become sloppy and stop carrying about things like modularization and API design, immersing themselves into sloppy code and factories of factories. E.g. no project should ever get to millions of lines of code, because no developer is able to keep it in one's head, which is why monolithic code bases are a mess. If you're not splitting your project in multiple modules/libraries, you're doing it wrong.
And such users can't see it, because they are developing in languages in which IDE usage was encouraged from the start (e.g. C#, Java), so libraries are naturally developed with IDEs in mind, being really hard and frustrating to use them without an IDE, creating a vicious circle. It is also my opinion that IDE "users" (because seriously folks, many of you are not the kind of people that can adapt their environment to their needs, therefore you are just users) have never tried to develop in Vim or Emacs in combination with a potent REPL, plus the Unix toolchain. Unfortunately for you particularly, you'd also have to change languages and immerse yourself in the Unix culture for that to be a pleasant experience. But seriously, try it sometimes, you might just like it.
Note that I'm currently using IntelliJ IDEA, from the same guys that are delivering ReSharper, the plugin that makes Visual Studio usable. IntelliJ IDEA is a really potent IDE. But many times I hate it and I can't wait to get back full-time on Emacs, unfortunately I have to use IntelliJ because I'm dealing with Java's ecosystem right now. Well, at least Java has Maven and SBT.