Feels like theres some cherry picking going on. eg whilst “the power rock of the ‘80s is… incredibly cheerful’ the 80s also played host to Joy Division and Suicidal Tendencies neither of whom exude incredible cheer (though the angst is expressed very differently). Similarly the cheerful rock’n’roll of the 1950s might be contrasted with the mournful blues and jazz which spawned it. Or what about the 50s novels of Richard Yates pretty bleak stuff compared with the life affirming tone of best selling contemporary novelists such as John Green and Becky Chambers.