Also, there is a difference between "easiest to learn" (e.g. uses keyboard + mouse) and "easiest to use" (e.g. keyboard navigation). In the hands of an expert, Emacs and Vim are more efficient than other editors--in a very real sense, they are easier to use, but only after you learn them.
Learning how to use an editor well enough to be efficient is an O(1) task. The benefit to using a powerful editor efficiently is O(n) to however much programming you do. Unless you don't plan on doing much programming, learning how to use a good editor is worth it.
There are some other reasons as well (e.g. Emacs is extremely consistent, customizable and supports every single thing you can imagine doing in a text editor, and then some). However, I think this is all secondary to just being more efficient and not having to think or switch contexts (e.g. never going from typing to using the mouse to using the arrow keys and back to typing).
That does not mean everyone should be doing the laborious "move hand to mouse, do visual scan, click" loop several times to initiate every action, because that often ISN'T the shortest path from A to B.
vim isn't unnecessarily complicated for the people who really need it. If you need to extend and automate and customize to any significant degree, you will need an editor which offers scripting that hooks into most of what it does, which is unavoidably more complicated than notepad.
That is apart from matters of taste, which aren't a matter of complication so much as "I want to use multitouch gestures to perform editing tasks" or "I love LISP as a configuration language" or whatever.
I do not know a whole lot about sublime, but from a skim over the first few relevant google results it looks like it's got some power to it. If someone wants to learn that, fine. What I object to is the "just use gedit" in the article. That means no syntax highlighting, and frustratingly little power in the editor.
There are some things the mouse is very good at - picking from a visual display, describing relative motion. The mouse is only useful in programming to the degree that these things can be made relevant. I have every expectation that this fits some people better than others, but I do think that people frequently overestimate ease of use with the mouse and underestimate ease of use without.
The good part is that it'll ignore capitalisation, underscores, etc. and you can start typing something in the middle - "foo" will pick up Foo, foo, test_foo, widgetFoo, foobar and FooBar.