I think a lot of the themes explored in 99 were a consequence of cultural changes in the earlier half of the decade. Microserfs by Douglas Coupland and the general anti-corporate attitude of the rock scene both clearly suggested a shift from the pro-business Reagan years into a more negative (or at least ironic) view of 'the job'. The dot com boom exacerbated this and 99 was also the year of the WTO riots. Something was certainly in the air.
I think Jack White owns most of, if not all of, the copyright of The White Stripes' back catalogue. Quite a lucrative business if you can manage it.