Serato DJ needs to add HID support for XDJ-1000MK2. I mean the XDJ-1000s have it, I can't imagine it would take too much development time to integrate XDJ-1000MK2. This would obviously take people away from switching to Rekordbox, which is Rekordbox's ultimate goal. User retention is key at this moment when there is more competition on the market.
The USB stick and control tone is a hack but it does work for the time being, but it's no replacement for HID support