Fashions currently play an essential role in the sociology - and in the funding - of physics and other sciences (mathematics being relatively spared). A specialised subject (such as chaos, string theory, or high temperature superconductors) comes into fashion for a few years and then is dumped. In the meantime the field has been invaded by swarms of people who are attracted by success, rather than the ideas involved. And this changes the intellectual atmosphere for the worse.David Ruelle, Chance and Chaos (1991), page 71
This issue of fashions in condensed matter physics was also discussed by Sokrates Pantelides in a 1992 Physics Today opinion piece.