First, we had animated people in the terminals since Zurich, which was made in 2007...
Today, because of the memory-hungry airplane and memory hungry background sceneries that are now available (which weren't in 2007), we are always looking to find new ways to save precious VAS memory, not new ways to waste it.
When, and if, P3D will be 64 bit, the issue will then change into not adding too much stuff because of fear or OOMs, but not adding too much stuff in order not to kill the fps.