A WHO link I found claims that high-dose irradiation (>10,000 grays) is substantially safe and will sterilize food, but Wikipedia says this is banned in the US except for hospitals and NASA:
http://www.who.int/foodsafety/publications/fs_management/irr...
http://en.wikipedia.org/wiki/Food_irradiation#High_dose_appl...
Animals are treated as units of production in developed countries because this is what is required to provide sustenance at a scale that makes it economically feasible for hundreds of millions of people to eat better than ever before in the history of humanity. [1]
Seriously, how many times must we start over every time someone watches Food Inc.?
[1] http://www.ers.usda.gov/Briefing/CPIFoodAndExpenditures/Data...
And your link is only moderately related. Yes, we're spending less on food. Yes, we'd have to spend more on food to eat the same exact diet without factory farming animals. But it doesn't make any claim that we are eating better than ever before in the history of humanity.
* One is a moral judgement: Should we subjectively mistreat animals in order for humans to be healthy and prosper?
* The other is a scientific question: Is irradiation a safe and effective food sanitizing method?
Guess which one has dozens and dozens of studies to back it up? OP posted a few links, but try the CDC's take on it: http://www.cdc.gov/ncidod/eid/vol7no3_supp/tauxe.htm
Look at all the unrestrained horror and apocalyptic glee surrounding Fukushima and answer that question for yourself.
I know it isn't the same thing, or even the same kind of thing. You know that as well. However, convincing the masses of that will be the work of at least a generation, and, even if it is widely accepted, there will always be people who will be opposed to it for the simple reason "NUCLEAR SCARY!" and nothing else.