Emacs is a classic piece of software that has stood the test of time. It has been around for decades and will probably be around for decades to come, so though it has a bit of a learning curve, it’s well worth the effort to learn.
Although my original motivation for learning Emacs was in pursuit of the ultimate clojure IDE experience, I’ve quickly realized it is extremely valuable as a general-purpose editor. My background has always been as an IDE guy (eclipse, IntelliJ IDEA, etc.), aside from knowing just enough vi to get around on the command-line.
Here’s some of the reasons I chose to invest in learning Emacs whole hog: