I would think it had to do with that and ALSO the diminishing returns of pulling more of the world's population into market systems (which is getting a hell of a lot closer to saturation), population growth (which is slowing), rolling out already existing technology and infrastructure to areas that didn't have it, finding interesting and useful ways to arrange matter that require large amounts of money to be spent, and general diminishing capacity for exponential growth in a world that is becoming much closer to 'full' in terms of rates of what we can suck from ecosystems and the ground. Maintenance cost for all of our established physical and social capital we have built up also has to be considered.