One book of poetry is not enough to make such a statement. As another commenter mentioned, poetry is a hard genre not only to break into but to make money. There just aren't enough poetry readers. I write science fiction novels and have for 12.75 years, and I make all my money (except for audiobooks) from KDP. I currently have 77 novels and box sets published with lifetime earnings of $1,540,000. It can be done, and KDP has been my golden ticket. If you want to be a writer, you need to go where the market is. It's a business just like everything else. Expand your horizons and see what happens. But I can tell you from experience, KDP is NOT a scam.