It's not viewed as waste, though. It's viewed as investment. The infrastructure being built employs a lot of people in the lead-up, the public transport of the host city gets upgraded, it's an opportunity for the host city to become more well-known internationally and boost tourism for years afterward. Local businesses ought to do quite well out of it.

I'm not particularly a fan of the Olympics, but I can see why cities bid against each other to host it.