The wife is like a mirror. If she complains, the mirror becomes blurry. He can blame all the troubles on her and forget his own problems. But if she is humble and responsive then the mirror is clear, and he can see his own faults. He might not admit them, but be assured he sees them.
1 Peter 3:1-5
Likewise, ye wives, [be] in subjection to your own husbands; that, if any obey not the word, they also may without the word be won by the conversation of the wives;
While they behold your chaste conversation [coupled] with fear.
Whose adorning let it not be that outward [adorning] of plaiting the hair, and of wearing of gold, or of putting on of apparel;
But [let it be] the hidden man of the heart, in that which is not corruptible, [even the ornament] of a meek and quiet spirit, which is in the sight of God of great price.
For after this manner in the old time the holy women also, who trusted in God, adorned themselves, being in subjection unto their own husbands: