It's no so much that he cares too much about IQ it's that he doesn't realize that IQ isn't deterministic as regards the economy, quality of life, and overall success. It's one component among many equals. Furthermore, any presumed difference between national IQ's is based upon very limited collections of data and the utility of said data is further diminished by the fact that for low income countries a majority of that difference is easily explained by inadequate nutrition levels. Not to mention that there is a much larger difference between individuals than there is between groups. Futurist at best has a highly deterministic and simplistic world view that is plain wrong and at worst his view is a nefarious veil for ulterior motives.
Yes, it would certainly be nice if we had more detailed and more reliable IQ data for the developing world; I'm certainly not disputing that. I'm also not disputing your other points here--as in, that environmental differences could significantly hold back some Third World countries and that the IQ difference within groups is much greater than the IQ difference between groups is. Still, the average IQ difference between groups is noticeable enough to make itself visible--for instance, in regards to comparing the economic situation of US blacks, US Hispanics, US whites, and US Asians.
There's also a correlation between IQ and some other things, such as life expectancy:
This correlation appears to mostly be due to higher-IQ people on average having better genes:
However, this correlation is NOT perfect since otherwise US Hispanics would not be living longer than US whites on average in spite of US Hispanics' lower average IQ.