I think the location has to do with the type of gameplay involved. In RE4, it was set remotely but you really spent ALL of your time in the one location. RE1 spent the entire game in the mansion, and the police station in RE2 was a huge maze that took most of your time to search through. I think if RE7 were to go back to the old style of searching and puzzles it would have to be in one location, but RE6's fast moving more linear style meant that they had to keep changing it up. It also allowed them to introduce the J'avo while still having classic zombies in the game. They couldn't have put them in the same place, but they obviously had this idea for a true military use of the virus and wanted to implement it without leaving zombies out of the game completely (because that would've been weird =p). I do agree I preferred having to look around a lot, and not jumping from one place to another, but I truly believe that they will start to fall back to this style in future games.
Also, I think that storyline wise it makes sense to move it to places like Africa, Spain, China, etc because for EVERYONE to be experimenting with new viruses in America.... well it would just be too obvious and no one would be able to follow through with their developments lol. Especially after the Raccoon City outbreak. So they have to take it to some remote location to do more research. Even RE Code Veronica was set in Europe.
Also, I think that storyline wise it makes sense to move it to places like Africa, Spain, China, etc because for EVERYONE to be experimenting with new viruses in America.... well it would just be too obvious and no one would be able to follow through with their developments lol. Especially after the Raccoon City outbreak. So they have to take it to some remote location to do more research. Even RE Code Veronica was set in Europe.