A lot of people are complaining—and rightly so—that Nintendo is screwing DSi owners with this 4-inch “it’s for old people eyes, honestly” redesign thing. It’s all speculative wisp-of-a-ghost-of-a-rumor stuff, of course, but if it is true, I’m still left wondering a wildly obvious thought: Why the heck weren’t there 4-in. screens on the original DSi t...