No, it's not that her concept needs to be retooled, it's the fact that you guys don't know how to play Zelda, and in fact, no one really does considering people throw her under the bus because of their belief that she's bad in concept. The fact of the matter is that people just aren't used to her type of character whatsoever. People complain about her lack of a reliable projectile, her mobility and the sweetspots on her moves, but people ignore quite literally everything else about her.
I can tell you guys straight up that she has decent projectiles, but they're unconventional projectiles, much like Izaw showed in his Art of Zelda video. They're not meant to be used on stage most of the time, but Phantom Slash could be used for the 2-Frame Punish, and it's a pretty good kill move and a good move to keep opponents away from Zelda if uncharged. Then you have Din's Fire, which is not meant for on-stage play, and seems to be only for killing opponents with its epicenter.
But then her mobility, which people automatically call a problem. Okay, she has bottom 10 running speed, but her aerial speed is in the top half of the cast. That means her general mobility between those two things is above bottom 20, probably.
And then you focus on the sweetspots of Zelda's moves. Okay, if you think about it, it's reasonable to have Zelda have such attacks considering that they aren't her only kill moves, and considering that she has many moves that link into them. If you knew how to play Zelda, you'd disregard her "bad design" and do something with her! Her aerial mobility is there, her swift attacks are there, her other kill moves are there, her combos are even there, so don't just focus on the moves that you call "bad in design" and focus on literally everything else, especially the things that set up to those sweet-spotted attacks or projectile attacks.
I mean seriously, time and time again that Zelda's brought up, it's almost always followed by "her bad concept". No one should have the right to say a character has a bad concept if all the characters could be considered bad in concept for being too broken or too underwhelming, or just middle of the cast.