The reason they made a separate hub is because it works better that way. Don't assume they're just bumbling idiots who haven't thought this through. It's done that way for a reason.
E3 isn't a consumer show at all. It's a press event. They're not selling it to the attendees at E3, they're selling it to soccer moms and six year olds, and are relying on journalists to do their jobs and report on it accurately even if they're not personally the target audience.
Wii sport wasn't a surprise. It was equally obvious. It's clear that physical gaming requires a sports title. We've certainly had arcade machines with sports titles for ages (golf, skiing etc.).