>> We know so much more about things than we did before, <<
Do we really? Serious question.
>> and technology has actually become so much more complicated, <<
Compicated technology is not always good technology. Often making a big step forward involved taking a step back. Undoing the mistakes of the past that cloud the true basic prinicples at work. Advanced aircrafts (Scaled Composites type stuff) often don't look like the classical airplane design that florished in the huge growth in airplane tech. Also vectored thrust vs. control surfaces... The new Transmeta chips with code morphing technologies have many less transistors than the current Intel breeds. The also consume less power and run cooler while maintaining comparable speeds. Planing hull kayaks. There are those who say displacement is better, and they only reason they do is because it is familiar. The clever solution is usually taking a back seat to the conventional solution until the leads possible by "conventional" means are exhausted. Why not be clever to begin with? Yes, I know sometimes other technologies are holding back the developments.
>> that in order to be effective, one has to focus on some small aspect of life (technology). <<
I feel quite the opposite. In order to REALLY be effecive, you should know about a many different things as possible. I never hire people who have a very tight focus. I like people who think and wonder and find out about everything. THAT is a good basis for effectiveness in a technological word. My opinion. Yours may vary.
>> There just isn't enough time to learn about everything and still know enough about one or two things to be successful. <<
Disagree. I'd feel like I was boasting if I were to make a list of all the disconnected things I know about. I'm not alone in that. There are a lot of people on BT who know a lot of things about a lot of things. THESE are the people I'd hire because I know they can solve any problem thrown at them. They don't look for solutions JUST in the most obvious area, but also in different ones.
You can't think outside of the box if you are sitting in one. The more broad you are, the better prepared you are to solve problems. That's just been my experience.