I think it's a mix of getting old, "stuff was better when I were a lad", and things moving else where.
When you were younger, you were almost certainly more excited about things which were not nearly as new as you thought. This is simply because when one is younger, one has less experience, so more things appear new. Where your older self now sees a rehashed idea from 1957 with pretty graphics instead of punch cards, your self 20 years ago would have seen a brilliant new idea. I think this inevitable and it's why us old farts don't instantly jump on the latest bandwagon. We know, for example that Hadoop is not actually a world changing thing: it's yet another distributed computing platform with plus points and minus points and which doesn't solve the killer latency problem all that well. A friend of mine mentioned that the rather fashionable startup he's minioning for, they worked through many of the most fashionable platforms, and ended up on the deeply unfasionable MPI because they had a latency sensitive problem and it turns out none of the cool new tech solve the old, hard problems all that well.
The second thing is due to good old selection bias and you remember the good ones from the days of yore that amounted to something and have forgotten the mounds of insane bullshit which I'm sure were there. This is not surprising: who *would* remember a mount of insane bullshit from 20 years ago.
And finally... something completely opposite. Industries do move in cycles. Things settle down and solidify/stagnate, which is what happened from the golden years of home computers (the 80s) moving into the beige box era. Sometimes all it means is that you have to look else where for the genuinely inspiring things that feel like they might change the world.
Despite teh bad rap it gets, cheap 3D printing is there for me. It's like the early 80s of home computers. There's all sorts of home-garage based operations. The pace of change and level of innovation is immense. Many operators can pretty much assemble one from scratch (you pretty much have to to keep the sodding things running), but it's also moving into a more commercial realm, as cheap, decent commercial ready made ones are slowly squeezing out the little garage companies. None the less there are plenty of genuinely interesting and innovative things happening and it's visibly improving month-by-month.
I also do some work in the small end of aerospace occasionally (not the big contractors) and I can assure you there's some amazingly exciting stuff coming down the pipeline. Read up on Skylon and the Sabre engine for example.