Actually, even with a higher standard of living, I wouldn't be surprised if very cold or iced beverages are still not that common. (Someone with more recent experience can let us know) It's a cultural thing. Maybe it's not a big deal with the younger generation anymore, but traditionally Chinese don't drink cold beverages anyway. In our hotel room, we would always find a thermos bottle of hot water.

There's also this interesting idea about how you will sweat less in hot weather if you drink hot beverages and keep your body temperature closer to the outside temperature. Interesting idea, but after a long, hot day of sightseeing, the last thing we wanted was a nice cup of hot water!