I remember reading an interview with Carol Kaye where she talked about her work as a session player. Back when she was recording with the Beach Boys, the musicians and studio engineers used to laugh at the songs they were asked to record, viewing them as mainstream, temporary trash. There was actually a quote along the lines of "can you imagine people listening to this stuff in 50 years?"
What is 'good' is purely subjective, and those who think that modern music won't have a lasting legacy are the small minded ones IMO.