There's a car analogy here; let's see if I can do it right, considering I just woke up 20 minutes ago.
Before WWII, the automobile was something a fair amount of people owned, but didn't do much with by way of "hacking". The real automotive hacking was done to just keep the damn thing running and reliable.
Post WWII is when the kids of the day started hacking their cars to build hot rods, and they did it to get girls and show off. Most of them, though, tweaked their hardware and horsepower simply to see how far they could push the machine.
By the '60s, hot rods had evolved into muscle cars. Horsepower purists were applying what they knew about hacking the previous generation of automotive technology to the next generation, and managed to Frankenstein a whole new animal--some of these cars could get you killed if you didn't know what you were doing.
Detroit took notice. Fifteen-plus years of kids hacking their engines defined a trend--a trend which said, "give me more horsepower!" Chrysler, in particular, took this to heart and made the Barracuda barely street legal right off the assembly line. All it took was a few small tweaks to turn your showroom car into a full-blown monster of a muscle car.
Chevys took a little more work, but the replacement parts required were dirt cheap, and remained so for a very long time.
By the 80s (or thereabouts) imports were gaining a foothold in the American market, and the muscle car was slowly being phased out for the Ricer. It didn't help that the cars which used to be so easily modified were now rolling off the assembly line with computers under the hood.
Nowadays, cars aren't nearly as easy to tweak as they once were, partly because of the computers, but mostly because they now come with most of the tweaks pre-installed. So, what you get nowadays are the old, die-hard muscle car enthusiasts (who have been pushed well out of the spotlight), the "I live my life a quarter-mile at a time" Ricer morons (who tweak their car with ridiculous body kits and the occasional nitrous oxide bottle, rather than any meaningful auto hack) and the crazy, wild-eyed guy who lives 20 miles out of town and spends his weekends trying to get his old Accord to give him 100 miles per gallon.
The hot-rod kids are still out there, they're just older, wiser and overshadowed by the Fast and the Furious.