At the time, during the ‘50-’60s, Fulda Gap was the easiest route to use for an invasion of West Germany and Europe. Profit had nothing to do with anything. This route was in the Soviet’s theater war plan. Evil also had nothing to do with anything. If the Soviets had wanted to take Europe, using the Gap was the best and quickest way to overcome any opposition.
There was nothing to do but attempt to defend against it, even though at the time, US and NATO troops were hopelessly out-numbered. Further, US troops were often overheard passing position, strength, disposition in the clear, making any attack fruitful for the Russians, who were bragging about obliterating the West in a nuclear exchange.