Originally Posted by quzar
There are many more reasons to have games not be reason free:
ratings systems in each territory
import/export problems
restrictions in certain territories on games (in germany games can't show blood)
marketing/boxart/cart-disc art/instruction books
to give an example, if there were no region restrictions, many domestic (US) stores would carry all sorts of japanese games that are not intended for US audiences which may or may not contain dialog or depictions that would be controversial here. By placing restrictions on regions, game companies can make sure that they are not liable for anything like that. IIRC if a game is not rated by the ESRB, there is no obligation for the local seller to check ID regardless of the local laws.
Basically having games specific to regions is done out of necessity.