Because an IDE isn't just a text editor. It takes a nontrivial amount of time and people to get a good IDE running. If you consider that a lot of this time is s

Because an IDE isn't just a text editor. It takes a nontrivial amount of time and people to get a good IDE running. If you consider that a lot of this time is spent on features that have already been implemented somewhere else, it makes sense to leverage an existing project and then, on top of it, work on hard features that really have an impact on Android development - as is the case with the new Instant Run, for example.