Some companies rent dedicated servers or virtual servers in China or Hong Kong or Taiwan, and because it's close to them (same country or region) they get fast speeds and everything looks good for them when they try to access their wesites.
However, lots of ISPs in that region use cheap providers of bandwidth to move data across the oceans (Cogent, Tata etc) which means big latencies and saturated links and to top that off they oversell the external bandwidth to their clients. That's how some people download with very slow speeds from such websites.
My perfect example for such a case was C-Media, their website was in Taiwan and a few years ago, the download speeds from their servers were in the range of 2-5 KB/s.