Even though Mario has many more games than Link, a bigger majority of The Legend of Zelda franchise has more critically acclaimed games. Link's greatest achievement was in the game Ocarina of Time, which is voted one of the best games in the world.
Mario has had it's time and The Franchises worst game was around the Mario Galaxy 1 & 2. Around that time Skyward Sword came out and people are still buying that game. A well amount of games are being bought on eShop.
Reasons why Link should be the new face of Nintendo
There are many reasons why Mario is the face of NIntendo, but there are many more reasons for LInk.