Because the Witch of Light is flawed herself.
(Edit: This has gotten really long lol. Added a tldr at the end)
Now, mind you, this has not been outright stated in Witch's Castle yet (I think) but I can explain why I see it as canon.
In the newest First Saga chapter in Witch's Castle, the one about First Salt and Sugar, we see both of them come to terms with the fact that their "perfect happy world without conflict" was not possible from the beginning. That the world is shades of grey and it is not right to simply lock away all the evil people and think the problems are now solved. They said that their desire to have control over everything might have ended up hurting everyone instead.
This shows us that the Witches themselves are beginning to understand that what they wanted for the world was wrong. The flashback in which Salt and Sugar talked about this was also the one where they were creating the Soul Jam. Meaning they now disagree with their past-'Soul Jam creating'-self.
But there is one more thing to this scene. Salt and Sugar both mentioned *why* they wanted to create a hero and a perfect world. It's because of the Witch of Light.
The Witch of Light is their hero. She saved all the other Witches from certain death and it seems that, for Salt and Sugar, a hero like her is a must for a new world. She is their savior. And what did this person that they idolize say to them? The WoL told these two that a perfect world without conflict is possible. And I think that, just like the twins, she actually believed it. But she is not a god. She is just human. So a future lesson for crwc might be that the Witches do not only learn about their own mistakes, but they also recognise that the WoL is flawed just like them and shouldn't be put on a pedestal. We've seen what that kind of position does to a person: The Beasts were even specifically made for that job and yet they still crumbled under that weight. The WoL might be silently breaking under that pressure too.
My rant is now gonna go a bit off the rails here, but I'm still going off of all the things said in the WoLs story. So bear with me and enjoy my theory/headcanon lol
The twins did mention that their need to control might actually be hurting the world, but that control was born and/or amplified by the WoL, since she shared their view. So her world of "Free will" might actually not be as free as she thought.
We already know that the Witches have some pretty fucked up backstories and the WoL seems to be no exception. We see people come after her with spears and her then having to leave her kingdom. What she saw outside her radiant kingdom was also not great, since they put First Grains dying village right next to the kingdom. So I assume this is a case of "rich people hoarding their wealth and everyone else dies of poverty." The WoL did mention that the world was breaking due to "ignorance and greed"
This "ignorance and greed" part can actually be seen in two different ways. One is of course "rich ignoring poverty" but then there is also the Witch Hunt. "Ignorance" is the humans seeing Witches as monsters and hunting/killing them. "Greed" is the part First Grain mentioned; they wanted her powers. So being able to use magic is bad and wrong, but having a Witch as a slave and use their magic for your benefit might not be. Typical rich people logic. First Berry also mentioned that the wanted to "take her away." The humans probably wanted to claim that abundance for themselves, but if the Witch does not comply then they simply kill them.
I am getting off track lol. So basically the world sucked and the WoL is probably very traumatised.
And what did the WoL say she'd do? She wanted to "cleanse the world of darkness" and she got 12 Witches to "share her wish." But the thing is, locking yourself away on a remote island, turning it into Willy Wonkas chocolate factory and then playing the Sims on it might not be the way to go. Like, the moment I learned about her story I was like "Wha- Cookies? How are cookies gonna help cleanse the human world of darkness?"
So my theory is, that the whole of Earthbread is actually a coping mechanism. The WoL has seen so much fucked up shit, has seen so many people die, that she simply wanted to save *someone.* To actually have the control to give people a good life.
She apparently did try herself to live a normal life baking non-living treats. At least if she truly is the Shadow Witch's grandmother like it is heavily hinted at in crwc. The WoL had a small bakery, which was immensely popular, until the humans accused her of using witchcraft. Maybe she did, maybe she didn't. All I can say is that the WoL most likely didn't sell living cookies to humans for them to eat.
But maybe that's the moment she began to create the magic that'd bring cookies to life. If she had a bakery then she already loved baking before Earthbread. And if the humans once again turned their back to her then her baking was all that was left (plus the other witches of course.) So her view might have slowly drifted to cookies instead of humans, because creating living cookies was simply much more kinder and more successful than helping her own people.
In the Salt and Sugar story there was a Witch that said "This is not important right now!" I think we can all agree that that was First Egg. Now, not to sympathize with the villain, but as a Witch who "bowed before the WoL, sharing her wish to cleanse the world of darkness" it might be a bit frustrating to see your leader focusing all her time and energy into creating living cookies. Instead of, you know, saving more Witches and ending the Witch hunt.
The WoL is the princess too, so her parents are the King and Queen. And what can a King and Queen do? Correct. Order Witch hunts. Man it would be fucked up if the army that came to capture First Berry was actually the one that belonged to the WoLs kingdom. They do seem to hoard wealth after all.
So of course First Egg is pissed at her; the Witch of Light is completely ignoring the human world and the suffering in it. She is not actually cleansing the world of darkness like she promised. In conclusion: our dear princess is indeed, very flawed.
Thank you for coming to my ted talk. This has gotten really long lmao I'm sorry.
tldr 1: The WoL is just a human. She didn't know the Virtues were flawed.
tldr 2: Creating living cookies does not cleanse the world of darkness, but is instead a coping mechanism. The WoL is ignoring the cruel human world and is instead focusing on a "perfect world" were she actually has enough power to help everyone. She is just as flawed and traumatised as the other witches.
