Yall DO realize Gohan NEVER liked fighting right?
Gohan was never supposed to be Goku Jr. That's a little more Goten's style, but neither of them have the thirst to be the best like Goku does.
Goku is a parent-less orphan who was training and living by himself since the age of 7. His only father figure was Roshi, who was his sensei, and his closest friend Krillin was his training rival. Fighting and training is LITERALLY all Goku knows.
Gohan grew up with an overprotective mother who loved him and the last thing she wanted for him was to fight. Throughout the entire series the main arc for Gohan was to overcome his desire to NOT be a destructive person, but to uphold his father's morals of dignity and decency. He fought ONLY to protect the earth and his loved ones. Not ONE single time did he ever fight out of personal need or gain. He trained with Piccollo because his father's dying wish was for him to be trained for Vegeta's arrival (and Piccollo kidnapped him) he went to Namek get the dragonballs and help bring peace to earth. He fought Cell literally because his Father believed in him and knew he was the only one strong enough to defeat him. He entered the Martial Arts tournament because he knew that was the only way to spend time with his dad (remember Goku only had 24 hours on earth) and because Videl blackmailed him into training her. He fought the Demon King to protect earth, he fought Buu to protect earth. NEVER out of pleasure for the sake of fighting.
So all of this "Gohan is a nerd" talk is absolutely right. That's what he always WANTED to be and what he became during peace times. A responsibility, family oriented scholar.