The reason they had guards on it was to keep the other guards from trying to escape.
Tell that to the guards who yelled at me...when I didn't realize I had wandered into "no man's land."
As you know, the East Berliners tunneled under the fence...and had to hide the dirt.
You cannot compare the terrain on the TX boder with a fence down the middle of a city. Trust me...because I've seen both!
Rather, the Russian designers set the whole system several feet back into their zone of control ~ in some places a whole lot of feet, but still not all that big an area. Remember, the objective was to STOP MOVEMENT, not control small blocks of farmland or forest. And in some places it seemed to me they'd "curved the line" to improve their field of fire on their own side.
Most likely anyone crossing the actual border and stepping in the East Bloc would find an understanding VOPO willing to shout at him to "get back scheistkopf" ~ or a Russian willing to tell him the same thing.
They all had a vested interest in NOT having to go out there to pick up the pieces from some fool who'd blown himself up. It takes more than a day and is not done without risk. There were little poppers everywhere, plus the bigger antipersonnel mines, plus the vehicle mines ~ and nobody on either side of the border wanted to be bothered with any of them going off. Maybe the big dogs in Moscow or Washington did, but not the guys down on the border.