Well I like the not Wind Waker style better, and I like Twilight Princess more than wind waker gameplay wise as well. so I wouldn't say it would be sacrificing integrity to make a game like those. I like Skywards Sword Watercolor Palette though too, though I think some of the character designs could have used a bit of work (Majora's Mask could have benefited from not reusing so many assets from OoT :P). I think discrediting TP, OoT, and and Majora's Mask artstyle as CoD like is dumb, it's more realistic, but it's still heavily stylized.
You could argue that they sacrificed artistic integrity from their traditional zelda style to make games like WW and Skyward Sword appeal to nintendo's stereotypical fanbase and that idea failed if you want to play devil's advocate (not what I believe, they just wanted do do things imo).
As for using sales as a justification to choose between two artistic paths all things else considered equal meaning people want one more than the other. I don't think I have to answer that. What would you do? The assumption that I think is wrong here is that WW is artistically better and they want to do it that way more than a realistic take on Fantasy like LoTR, or the 3 zelda's I mentioned.
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