A reader writes on different expectations for rock stars and athletes:
There seems to be a pretty straightforward answer to this double-standard that doesn't require any mucking about in paleoanthropology. Athletes are typically associated with hard work and achievement; sports competitions are typically institutional and often government-sponsored events; and athletic competition thrives on order and rules. They are the champions of the values of organized society, which makes them excellent role models. As such, society will expect them to be well-behaved. Musicians, or at least popular musicians, are the polar opposite: their success is associated with creativity and inspiration, their excellence springs from innovation and subversion.
But most importantly, one of the greatest things that pop and rock stars sell is an anti-social image of extravagant hedonism or rebellion (and frequently both). Part of being a fan is to indulge in these things that aren't generally acceptable in polite society. This double-standard is not a bug: it gets to the heart of what it means, in the popular imagination, to be a musician and to be an athlete.