I agree, I wish more people understood databases and storage IO at least as well as many understand network IO. The recent rediscovery of buffer bloat and latency for example hasn't seemed to happen for storage, people talk like MB/s is the only stat that matters when it is often the least interesting.
I've struggled with this kind of issue in the past when trying to understand the performance issues and needs of a large in-house that I supported for many years. I got it wrong many times and the simple estimations that might have helped only look simple in retrospect. There is a lot of pressure to treat databases and storage as a black box until you ask more from it than it can give.