Your telling me that an elite athlete cant throw 500 strikes in a 25 minute period (with 4 1 minute breaks) without gassing when his opponent does nothing? Do you think Conor gasses on a heavy bag? Conor doesnt have the best gas tank in the world but the reason he gassed in the past does have something to do with what his opponent does.
In Diaz 2, it was because of the body strikes (Diaz focused a 3rd of his strikes to Conor's body). Same with Mayweather. He was tired against Mendes because Mendes made him grapple (Conor has one of the lowest grapple stamina ratings in the game because of it).
My issue isnt that the game forces you to do things to drain your opponent's stamina. My issue is that other things like strike output and misses caused by simple movement or blocking dont drain enough stamina.