I see your point but no.
First off, the Galaxy games were great and sold really well.
Next, Mario is also the face of Nintendo because his games can be played by anyone. For the Legend of Zelda, it requires a higher age group. A 6 year old can't possibly play Zelda, but my 6 year old sister can play (and does) a lot of Mario games.
Also, you can't take Link and do what you want with him like Mario. I can't possibly see Link playing "Link Party" like Mario does.
Nintendo is a company aimed towards families, so Link isn't a good fit at all. I fact, I don't think anyone can replace Mario.
Even though Zelda is amazing, I highly disagree