Even if it was f8ish, had IS, and a USM...sell in droves, no?
No, because f/8 lenses will not autofocus on most Canon bodies. As for an 'affordable' 600mm f/5.6 lens, that means an iris diaphragm of 107mm, so it's much like a 300/2.8 lens. The only way to make a truly affordable long lens like that is a mirror design, and that has numerous IQ and performance issues.
Given the recent price trends, it seems apparent that Canon is moving in the other direction, the complete opposite of affordability. 
Note that the 24-70 price increase was only 10,000 Yen, about 5%, in Japan.
What you're seeing with the price increase in the USA (and perhaps elsewhere) is the drop in value of the US dollar.
Essentially what we're now seeing was always going to happen. In response to the 2008 financial crisis, the USA effectively printed a lot of money. Normally it is only 3rd world countries that do things like this, but it (price increases) had to happen. Technically, the "inflation" has already happened. What we're just starting to see is the impact of that on the market place.
The comment about this being a record year for new Canon lenses might be their way of solving this problem: rather than push the price up on many of their lenses to reflect the change in exchange rates, simply deliver new products (lenses) with new prices that take into account new exchange rates.
If the problem is that lenses are now relatively more expensive for you then start talking to your boss/bosses and co-workers and saying that prices of things are going up so you need to be getting paid more.
In other words, the large changes in prices in the USA have nothing to do with Canon, so don't blame Canon.