I think controls are an interesting point. The touch screen controls for the DS Zeldas actually made playing them easier and simpler than ever before. You tap to move, you tap to attack, etc. It was very casual, and the most complex movements involved basically drawing lines on the screen.
On the other hand, Skyward Sword is a really interesting mix of traditional movement controls with relatively complex or advanced motion combat. The sword fighting in particular requires more precision and coordination than ever before, since you have to watch enemy patterns to see which directions they're blocking or moving, and then strike to match.
It's also interesting that a lot of the tools and skills have their own motion control schemes, many taken from Wii Sports Resort. While they are all extremely natural and fun, it remains a barrier of entry for people who aren't great at core videogames and remembering many different rule sets and instructions. Wii Sports Resort tells you the rule for each minigame before you play them, and those are the only rules for that entire minigame. In SS, you have to remember how to control each different tool and be able to pull stuff off as you switch between stuff.
I have no idea if such things will have much of an impact on the actual accessibility of the game for a larger mainstream audience, but they are still factors to consider. I don't think mainstream gamers have anything against motion controls, but it's all in how they are applied and presented.