I put, probably, 150 hours into Friends of Mineral Town for GBA so I know how much time you can put into these games. Sometimes I would play them for hours at a time, but mostly, just 5-10 minute sessions - water the crops, feed the cow, call it a day, return to it when I have another chunk of time to waste.
I never said anything about exclusivity, just inclusion - no reason there can't be a wiiware version. Afterall, it's Nintendo platforms that keep the series alive. But I think if there is a Wiiware version, it shouldn't be made for Wiiware and ported to XBLA/PSN but made for XBLA/PSN and ported to Wiiware because if they're gonna do it at all they should do it right because the XBLA/PSN audience might not go for a cheap port as much as something that was tailor-made for the consoles.
And you're still totally underestimating the size of the potential market. We don't know exactly how big it is until it happens, you think it's small, I think it's huge. Surely, though, we can both agree that these kind of games can survive on mediocre sales numbers so it's at least worth the risk