I guess it just depends on the genre. In artistic music dynamic contrast provides an expressive quality, or as Mark Kaufman puts- it "levels of performance intensity". Generally speaking dynamics in recordings of popular music, or gigs where popular covers are performed for the entertainment of audiences, dynamics may merely be used for effect, if used at all. Music as art; dynamics is essential. Music as entertainment; WHAT!! I can`t hear you; you`re playing too loud!