Back in the day when I started doing this (late 90s - early 00s), stationaty PCs were pretty much the centre of home entertainment so IT-oriented people faced the choice to either let things stay the laggy way they were or to start doing something about it. As overclocking used to be less mainstream than it is now, it gave significant bragging rights raising overclockers' self-esteem and propelling them to push it to the extreme.
I feel that these days people are less forced to make such choices due to variety of electronic devices they have access to. Even though sales of PCs might have increased over the last decade, these days almost everyone has a laptop and a smartphone to distract their attention, hence a lot less damn about PCs and overclocking is given.
As for the old crowd that is floating around - you can't expect people to do the same thing forever. At some point in time everyone will eventually realise that there are more interesting things to do in life than sitting in front of your computer.