I generally agree with both of you. I'm not sure the "late arrival" of Skyward Sword on the Wii had any significant impact on sales though. I have a Wii U and an XBoxOne now. If a game I like comes out exclusively on PS3 now, I would still get it on my PS3. I won't think "well, this is a late arrival. I'm gonna skip it". My Wii never collected dust until after I got the Wii U, and even if I had stopped playing it, that wouldn't be a reason for me not to buy a game I'm interested in. I don't understand that logic. If a new Wii exclusive came out right now and I could only play it on my Pal wii (I have an ntsc Wii and my Wii U is ntsc), why would the fact that I haven't played the Pal wii in 2 years be a reason for me not to get the game?

Because you are not casual gamer, fact is that large part of Wii owners were casuals, and probably after they moved to other platforms they completely abandoned Wii and Nintendo. Also huge impact on Skyward Sword sales has requirement of addon that people needed to buy if they wanted to play game. Also fact is that almost everyone alone could hack they Wii in 30 minutes without any money invested and play downloaded Wii games from internet.