Hey Stig, it's Dubai, you're not in Kansas anymore!!!
I too found it weird when I first arrived but hey, horses for courses as they say...
Some people like to fly their maid J since crossing between Y and J is discouraged, therefore easier for her to come and attend to 'the children'. Which is nicer than dumping her in Y with the kids and living it up in F
380 is right, much easier to get onload on staff tickets in J, if you are so lucky to have that benefit.