Terror Zones being random keeps the game fresh. Sure, being able to control where terror zones are would provide the best possible gains, but it would become stale after a while.
@Shawmeck mentioned a good point about terror zones being the same for everyone in a region, having a concern that masses of people may flood the NA/EU/ASIA servers just because they are running an ideal terror zone area, which could cause a surge in activity, potentially overloading the region. To stop this from happening, I’m wondering if they should make Terror Zones random per account.
Another big benefit of making them random per account would be that it would promote group play… If friend #3 has an ideal terror zone and the other friends don’t, they could join friend #3’s game and run it together.