Because statements like “… Isn’t about graphics or frame rate; it’s memory” don’t make sense at all.

I get what you're saying but it does make sense actually. The Series S has incredibly under-powered memory which has hobbled a lot of developers thus far. It's the core reason why they can't get split-screen working right yet. Framerate/graphics are more associated with GPU performance, which is not as big of an issue for the S. Everything bottlenecks on the very small, very weak memory they provided.