Well, the topic title says "good Christian advice."
If I wanted good medical advice, I'd go to a doctor and I'd expect his advice to have solid medical foundation. If my doctor were to quote Martha Stewart regarding my prostate, I'd give him the side eye.
If my desire was for "good Christian advice," I'd want advice based on the word of the Lord, and whatever that is, it will have a foundation in scripture. I've read enough scripture that I expect I will recognize Christ-based advice when I hear it. The Holy Spirit will remind me where it's found in scripture even if the person does not give me chapter and verse. If I went to a guy complaining about a problem with my wife and his advice was, "You need to love your wife," I'd think, "Oh, yeah, the bible does say that."
I don't know why quoting scripture would be considered "arrogant" or why being unable to quote scripture should be considered humble. I rather think someone who must turn to scripture for the advice he gives is being humble in not leaning to his own understanding, but relying on the Lord for the advice he gives others.