and i remember in the 90s if you wanted to play records at an afterhours that plays house/techno etc it was paramount you dont trainwreck it was part of the flow , you didnt go to bars to hear the dj mix you went to hear the top 40 but at the rave you went to hear proper music mixed smooth and there was an art to it and the next consecutive dj mixed their record into the previous the music was a continuous mix all night into the morning it was a warehouse thing.
there are aceptable reasons not to and those djs payed dues in a dif way
but now adays its too easy to dj from the technical aspect.
there are hundreds of new ways to enhance your perfomance and the new technology is great for this provided a dj uses it but most ive seen dont
i remember when the djm 500 came out ppl were bonkers for the effects but id still bet my dozen biscuits most djs wont use the entire efx facilities on that mixer.
i guess i come from a dif place where decks/mixer/speakers/discoball was all that was needed to make it special.