>>532753395
Remember how Erika talks about how whodunnit, howdunnit, and whydunnit are all equally important and there's no solution to the mystery without them? Umineko gives you the why, and the who, but the how is abandoned. It's not a tertiary issue, it's the main plot of the series.
You have to read the manga.
Hence Ryukishi apologized and acknowledge his mistake.