Old joke. Something about a business man on a trip to Japan being provided with company for the night by his hosts. She’s screaming “bushada” so he bangs away harder. Next day he’s golfing with his hosts and gets a hole in one. They all smile politely, but tell him “bushada”. When he asks them what is means they tell him “wrong hole”.
But he's making a reasoned point based on military effectiveness.
He's not writing off swathes of people because their (insert here : gender/orientation/ethnicity/faith) automatically renders them lesser beings, or part of an existential threat to either British values or our combat capabilities.