This is true, but Captain Marvel was a reasonable, easygoing fellow. We see him having dinner at a friend's house, chatting with people on the streets, socializing comfortably. He could be embarrassed or jovial or thoughtful. In many ways, he was the most normal of the super-heroes emotionally, and I think if you asked him to cut down on the "Holy Moley", he would say, "Do I say it that much? Well, I'll try to keep an eye on it."
Of course, this is still another reason why he doesn't belong in the DC Universe...