Zelda Classic may not be sold for profit, but it is still a work that uses Nintendo's copyrighted material and trademarks. That makes it ruinous to Nintendo's Zelda franchise by creating brand confusion, and it could hinder future marketability of these games in the same way as emulation. Programs like these may be all in good fun to fans, but they are taken seriously from a legal standpoint by their copyright holders, and it is both disrespectful and dangerous to assume otherwise.

Simply because Nintendo has not communicated to you about Zelda Classic does not mean that you can presume they have granted permission for the use of their copyrighted material or trademarks. There have been numerous claims in the original Wikipedia article and talk pages that Nintendo either condones or endorses Zelda Classic's existence, but no proof has ever been provided for these statements; only conjecture. The program receiving mention on TechTV or in EGM does not substantiate any of these claims either, as neither of this productions are representatives of Nintendo.