Comentário oficial
It's not a punishment, more following the history of the product since when rekordbox was initially released, it was as a music management / export software for preparing USB drives to use with CDJs - not as performance software. As such, they never shipped with keys for performance mode even once it was released. It's also about user segment; the DJs using DJM-900NXS2's are also likely to be using CDJ-2000's, all of which are intended as stand-alone devices (much like the mixer, the CDJs don't come with license keys / unlock for rekordbox either). A DJ buying a DJM-250MK2 is more likely to be playing at home or for friends where the computer is also more commonplace and accepted.