Boring is clearly subjective. I can happily listen to several different performances of a particular piece of [Bach] piano music, one after another, and not get bored. Or listen to some fairly ambient music, without a great deal of rhythmic drive, and enjoy it.* Or recently I've been listening to a lot of lute music. I expect a lot of my friends would find that music boring, even among the ones who are big music buyers/listeners.
* And of course, sometimes I just want to thrash some rock music, or punk.
* And of course, sometimes I just want to thrash some rock music, or punk.