Technical and business limitations drove the design of MapQuest. That client computers had little computing power, bandwidth (on both sides of the pipe) was limited and expensive, and processing power on the server for a very low value user (per interaction) had to be meted. No one who used MapQuest didn't wish they could just smoothly scroll the map, but we were fine given many of us were on a terrible connection, ran on systems with limited graphics power (where even smoothly blitting a high resolution raster graphic was taxing), etc.

Every improvement (more computing power, memory, storage, bandwidth, or even business model, etc) in the industry invariably leads to many people all independently seeing the same obvious next step, many groups building the same eventual thing, and then the losers (from a market perspective) claiming that their ideas were stolen. It is the story of this industry.