Its gotta be an one of those unknown laws of the universe... you will inevitably have a derailment/pileup in the exact opposite corner from where you are. When you're outside of it, its 2 legs of the triangle to run and fix it before something hits the floor, vs straight line if you have direct access from the inside.
I take it you've not done a train show with a modular group. While following a train around sounds appealing, it ultimately gets old. You end up just sitting down somewhere. If you're sitting on the outside of the layout, you can hardly see anything. From the inside its easier to see whats going on, and avoid the above unwritten law. Sitting down and shooting the breeze with multiple trains running has to be the far and away #1 cause of accidents on club layouts.
Gain the space that would be an aisle around a table, and wrap the layout around the walls. In 30x50 you can put down a layout that you can easily walk into, without ever needing to duck under a single thing. Shape of an E, F, S, T and others are all possible to do without any crawling.