Your brother in law probably thinks his "amazing" things are totally banal, derivative junk!Caveat: Art is in the eye of the beholder, it's all subjective.
Actually, I have a personal anecdotal story on this.
When I was in high school I attended drawing classes at a private evening school. In my opinion I suck at drawing and everything I drew was awful. However, my parents kept everything, for some reason.
Years later, my sister married an architect who draws (and designs) amazing things. One day he went through my "paintings" and decided that he liked one of them so much, he put it on his living room wall. At first I thought he's messing with me, but after years and years of the painting remaining on his wall I have come to terms with the fact that we have very different ways of viewing the world.
I think we have all had that experience of a wife or friend go through our pictures and pick out a bunch of favorites that we could have easily deleted. I even tell them why it's no good. Comp is junk, it would take forever to clone out that stop sign...They find something in it I didn't, even though I took it. I have gone mining through old photos and even disagreed with my own previous choices a few times:)