I think there is probably a fair assumption that many makers use both the raspberry pi and Arduino. Until now the easy “apt-get install arduino” method only got you Aruidino version 1.0.1, which was quite old, and missing a lot of the more recent boards and features.
You could get a modern version running, but it involved getting the source, compiling, fixing errors, and other bothers. Now Arudio officially has a linux Arm version on their site! Get it here. This ran out of the box on both my Pine 64 and Raspberry Pi 2, all the new modern features and looks were there ready to go!