I don't think he's saying that a single species of insect will have specialists in many different roles. I think he's saying that there are millions of species of insects and each species usually specializes in one thing so that they can survive in a specific environmental niche.

I don't think specialization by humans is bad, but I agree that specialization can go too far sometimes. If the person being paid to monitor a tank of fluorine loses the ability to do their own laundry or hold a conversation because they are spending so much of their time developing fluorine tank monitoring skills it's kind of a waste. Part of the human experience is learning and doing lots of different things. Even if our economy rewards hyper-specialization that doesn't mean that a person's entire life has to be focused on their hyper-specialized job.

That's the whole point though: you don't need "to monitor a tank of fluorine compound so that it can be used to etch silicon wafers" if you're computing with clockwork or fluidics. (I'm not knocking silicon, just pointing out that there are alternatives.)

Also, humans are the only species that can run a marathon, swim a lake, and climb a tree. We are generalists.

Diversification is a huge luxury, which you can afford if you are worth over a 100 mil and focus your life on being diversified. Even then it's questionable whether you are able to bring it all together ala DaVinci, Alexander, Caesar, etc. Seems we are past that point in history.