You have to look at what science was doing then vs. what science is doing now. In 68, we were one year from the moon landing, which is a good "culmination point" for the massive postwar scientific advances that had revolutionized life in almost every way. Science in the fifties and sixties was about opening doors - think about it - TVs were in every home, streaming in information in quantities far greater than ever before, superphosphates and massive irrigation engineering was opening vast tracst of land for farming, labour saving devices were entering every conceiveable niche in the home, nuclear power was cheap, plentiful and safe, buildings were taller and more complex than ever, antibiotics had come out of WW2 as wonder drugs, Smallpox was being eradicated, polio vaccines had been developed etc. etc. etc. There are a million examples. And that doesn't even take into account more esoteric stuff like genetic and atomic research moving ahead in leaps and bounds.
In essence, the last thirty years had been about examining the potential of science and not finding any limits, and in the process making everyone's life better.
Modern science, particularly in the last ten or fifteen years, has been more about finding the limits of science. We know now that we're running out of phosphates for fertilizer, that fresh water is getting harder to find, that metal resources of stuff like copper are scarcer and scarcer. We have global warming people telling us that all those labour saving devices use electricity, the generation of which will destroy the planet. Chernobyl shattered everyone's nuclear idyll, so that's off the table as well. Science has also had much less impact on people's every day lives over the past twenty or so years than it had in the twenty years preceeding 1968. Walk around your house and find stuff that they didn't have in 1988. With the exception of your more advanced entertainment stuff (which often had less advanced analogues at the time) and the internet, you wont find too much. Try to imagine performing a similar experiment comparing a 1968 home to a 1948 home. Much more dramatic change. Even medical science, despite advancing in leaps and bounds behind the scenes, curing lots of diseases that most people wont encounter int heir day to day lives, it hasn't had the hands on impact it had had in 1968. Back then, we'd eliminated a lot of the major diseases of the time. In the last 20 years though, new diseases have jumped up to replace them (AIDS, Cancer, heart disease and obesity etc.), and science has failed us against these illnesses.
It's a cyclical thing I think. Ask again in 20 years and I think we'll be on an upward slope again - new sources of energy wuill have made the oil crunch and global warming somewhat less critical (I'm thinking hydrogen here), and stem cells will make organ replacement viable, getting around cancer in a lot of cases. Metal and fertilizer shortages I'm less sure about, but there are alternative sources we can tap if things get desperate - first low grade deposits that are currently uneconomic, then underwater, arctic and antarctic stuff, direct extraction from seawater etc. etc. Also, I think we'll start to see even more computer integration into houses and routines (especially as online shopping continues to gain acceptance for non-luxury items), which'll show dramatic, positive, "hands on" changes to lifestyles. Stuff like wireless networking and bluetooth letting all your gear talk to each other, true roaming profiles and customization, etc. etc.
In essence, I think the doom and gloom of today vs. the optimism of yesteryear tells you more about people's perceptions of science than it does the true state of modern technology, or the potential of the future - it's social, not so much scientific. I'd be particularly keen to see what the mentality would be in upwardly mobil countries like China and Malaysia and such - probably hugely more optiistic than most of the western world.
