If a speaker is ’brash’ at some point you’ll eventually tire of that even with electronia or rock. What’s being ignored is that there are some excellent recordings in these genres that easily reveal speaker problems. Once revealed you’ll always hear it and it won’t matter the genre!
The idea that a certain speaker can favor a certain genre is the biggest myth in audio. If its good at rock but sucks at classical, you’ll find that if you play enough rock recordings it actually sucks at rock too.
like i said earlier, i don’t entirely disagree, but it really depends on use case/frequency/duration - imo to call it a myth is a little strong ... lots of people with nice hifi’s don’t sit there for hours listening intently, some want the excitement of live music, listen for a while, get their thrill, turn it off
we need to be careful not to impose our own usage behaviors and patterns, think all folks do as we do - pleasure from a hifi comes in many forms, usage occasions, situations
not to mention people hear differently, some clearly more preferring or more sensitive to some forms of distortion/tonality than others