Blizzard intends to limit the number of games a player may launch within a given period of time and here's why:

The use of bots not only impacts the stability of the game service, but it also has an impact on the player-driven economy. While we regularly take action against accounts for the use of unauthorized third-party programs and bots, this additional measure will help us further preserve and protect the integrity of the game and economy in between ban waves.

Once this change goes live, we're looking for your feedback to help ensure that the limit is working as intended. If you encounter the "Input limit reached" message and feel you should not have, please let us know how many games you were creating and why. This information will help us ensure the limit minimally impacts legitimate players while still protecting the game against bots.

Read more over at the official Diablo 3 web site.