There have been a lot of good sound responses in here but I can't be arsed quoting them all.
There has also been some pretty mislead ones as well.
It may be easy to call it nostalgia but I prefer not to call it that. It may seem as though it is nostalgia just because simply you only see a handful that actually can sit down and admire the good old days when stuff was built to last rather than stuff that is just built to last through a 1 year warranty. You gotta realize that these handbuilt amps and such weren't mass produced. So, there wasn't one for every man, woman and child in every country in the world. But yet many of them are still kicking around being sold and being used. Some items in excess of 20+ years old. Not too many things you can buy today, be it anything electronic that can live that long - let alone in a car stereo environment.
Overbuilt and Underrated were about the two terms you could use to describe those things. Sure, they were generally ugly and bulky, but they were good. Real good. I mean seriously, who in the hell makes a 50WX2 amp for example, that weighs 10 pounds and made with gold plated circuitry? Back in the day, companies were competing to make the best, most robust and underrated amps that won comps etc. Now companies fight to stay alive by mass producing shite to increase their bottom line and keep them competitive without going under. Back then it was sort of a pride thing along with the business. Now it is strictly business.
One thing that bothers me is the first thing some douche asks me is how many watts are my subwoofers or amps. Those questions come from the inexperienced, or the baby boomers that came after the hobby took this turn for the worse. Who in the frig cares about how many watts I am running. All you need to know is its more than my equipment claims, and less than you imagined. But more importantly it sounds good.
Watts used to be a measurement allowing you to get an idea of component matching and competition placing, whereas now it's just about marketing....that's all. I didn't even know how many watts were the JL audio subs I picked up were. I just looked at them and said "they'll do."
Bottom line is nothing I or anyone else says is going to change the world. It all comes down to money and marketing. There are people who buy into a lot of crap nowadays and people who know a bit better. It's up to you to decide which person you're going to be.