You seem to think that Athens is the average post-Olympics situation, when you couldn't be more wrong. You really think Toronto would build a permanent volleyball stadium then let it rust afterwards? Come on, I know you can't be THAT obtuse.
Out of curiosity, do you know where the volleyball and beach volleyball are being held in London? I'll give you a hint... volleyball is being held at Earls Court, which (surprise surprise) existed before and 110% won't be "rusted-out" after the games, and beach volleyball is being held at a 100% temporary stadium at the Horse Guards Parade, which I doubt would be left to rust afterwards too.
But I guess Toronto couldn't find any existing venues to hold these events, or build temporary ones. No.. we'd be exactly like Athens! (Not to mention nobody should ever use that clusterfuck of a country Greece as an example ever)
In fact, I'd all but guarantee the only permanent venues from a games in Toronto would be an Aquatic Centre (Oh God what would we possibly use that for afterwards! Everyone knows swimming and diving doesn't exist in Toronto), a velodrome (which can be easily converted in many ways, or, you know, used to improve the program), and maybe part of the Olympic Stadium (we have no use for an 80,000 seater stadium, so no doubt it would be semi-temporary like London's).
Other than that we have Rowing/Canoe/Kayak facilities (Welland), many arenas and convention centres for boxing/wrestling/judo/taekwando/badminton/gymnastics/etc. etc., beaches for beach volleyball, stadiums that could host soccer/be expanded to host (I bet you didn't know that Toronto and Ottawa were used for the 1976 games), a lake for sailing, and a hell of a lot of space for temporary facilities. So no, we would not get "some direct link to a rusted0out volleyball stadium". Use common sense.