Kojima considered dropping the trope to help make the game more realistic, figuring that it could be replaced thanks to modern graphics capabilities. "Considering the console specs, it would have been possible to substitute with facial expressions and gestures," Kojima said.
Staff working on the game warned Kojima that removing the "!" would cause an "uproar," and Kojima opted to keep it in. In the same interview, Kojima also expressed a desire to embrace another series staple: "I want to include the cardboard box."
The more things change, the more they stay the same. Unless you're Snake's voice.