My premium status ran out and I did not renew it.
Its not that the game isn't fun; I'm still enjoying it and always enjoy getting those citadel hits. But the drive to climb the tech tree has died down and my enjoyment of controlling aircraft carriers has fizzled as the USN tree has very few squadrons and replacements up to tier VI and while I still have fun games in the tier VIII IJN Shokaku carrier, I hate always seeing a Lexington on the other side and having to dodge two powerful fighter squadrons every time. Still love battleships though, lots of fun.
The big issue is that with my new computer I've been trying out lots of other games that my old PC couldn't handle. Some first person shooters like Call of Duty: Ghosts and Advanced Warfare and some big games like Civ V (my old PC could handle it, but was very slow).
I don't see me giving up World of Warships entirely, just right now I feel I've run my course and need a break.