What did other countries do in the last Men's Olympic marathon? I looked at the Beijing results, and found the following countries had sent more than one athlete: Lesotho (3), Ukraine (3), Brazil (3), Kenya (3), Japan (3), USA (3), Ethiopia (3), Morocco (3), Finland (2), Russia (3), Eritria (3), Spain (3), Tanzania (3), Mexico (3), China (3), Italy (3), South Africa (3), South Korea (3), Guatemala (2), and possibly others, but I got tired counting. Wait... North Korea also sent three guys. And Nepal sent a guy with a 2:23 PB (set at the Beijing Olympics). Great Britain sent Dan Robinson, who's PB is 2:12:14. Libya sent Ali Zaidi with a 2:13:33 PB. Hem Bunting from Cambodia, whose road to the Olympics was as challenging as anyone's, has a PB of 2:25. I think you get the point; most countries send as many athletes as they can, by whatever means.
The men's marathon is the last Olympic event to be run, hence an especially symbolic one. The medals are given out at the closing ceremonies. It's understandable that Canada wants to represent it well. The Olympic motto is (in Latin) "Faster, Higher, Stronger" but it is equally about worldwide participation, as shown even in the flag's design:
The emblem chosen to illustrate and represent the world Congress of 1914...: five intertwined rings in different colours - blue, yellow, black, green, and red - are placed on the white field of the paper. These five rings represent the five parts of the world which now are won over to Olympism and willing to accept healthy competition.
Diversity is at the heart of the Olympics, which separates it from the IAAF World Championships or Diamond League. We are not short of exclusive events. Recall the 'parade of nations' is a huge part of -and possible point to- the opening ceremony. The Olympic motto is meant for one's internal striving, not to be served as a rejection notice, i.e. "sorry, you were not fast/high/strong enough".
Of course not everyone can join the parade; typically each country sends their best until the field roster is deemed 'full', with a maximum of three individuals per country per event, imposed precisely to maximize the number of countries without preventing a (perhaps deserved) medal sweep. The good news is that it is not hard to squeeze a few extra (thousand) people into a marathon, as I've noticed after running a few myself. With 42.2 kilometers of real-estate, there's room for a three-membered contingency from every country. This is not true for every event; the 5k and 10k run this way would be a catastrophe, hence stringent AC standards here would be redundant. But the standards are comparatively relaxed for the marathon in order for a maximum of countries to participate. This includes those that might not normally qualify for -or afford- the income-elite Dressage or sailing events.
The rules as set by Athletics Canada imply our athletes are special, but not in a flattering way. By not sending a guy who can run under 2:13 when many other countries do sends the message that they too ought to have kept their guys home as well. Or perhaps it is fine for them, but our standards are higher, even more condescending. A third answer might be that we only send 'winners' to the Olympics. I sympathize with anyone who might call us snobs.
High-income countries appeared to have comparatively fewer runners in the 2008 marathon. Australia, for example, sent only one person. Why might this divide exist? Do first-world nations, those without many competitive marathoners, worry the relaxed standards are a free pass to the games? In Canada's case this is not a marathon-specific phobia, as our self-imposed austerity shows in other Olympic sports too, like biathlon, where we also want to send only 'winning' athletes.
That Canada can afford to ship three people across the pond to race in London is without question. Adding extra hurdles beyond the necessary ones sends the message to our would-be marathoners (and other athletes too) that our best are not good enough. It would be a nice touch if Canada also refused to give out gold medals at nationals if the times were too slow. But seriously (am I not?), regarding the qualifying time AC chose, 2:11:29, such an awkward cut-off of makes the decision an obviously bureaucratic one. Was rounding to the closest minute out of the question?
An aside: Some refreshing Olympic spirit