Of course it'd never be that easy.

Flurry Heart returned to Twilight's old castle not long after freeing Tirek, when she came across Starlight Glimmer. After excitedly explaining to Starlight that reforming the other two villains have been going well, Starlight said something that caught her off guard. "Why?" It was such a simple question, one Flurry could answer with confidence. She explained that Cozy Glow wanted her friends back, and she'd always wanted to reform them- to make them feel like the world hasn't abandoned them as statues, but… It didn't seem to satisfy Starlight.

"Why take that risk? You know what happened the last time those three teamed up. I get Cozy Glow- she's just a filly- but Chrysalis? Tirek? Flurry, I've tried reforming Chrysalis, but… Some ponies- erm, creatures, just can't be saved. You know that, right? " Questioned Starlight as she sat down on Twilight's throne.
"But- they shouldn't just be left in stone for years! Discord already had to endure that, and the only reason he stayed the same is because- well, it's Discord!" Flurry Heart tried to reason, but all she got in response was a head tilt.
"If even Twilight couldn't get through to them, maybe they deserved it." Starlight shrugged. "In fact, I'll turn them back into stone myself. They're too dangerous to be left roaming around!"
"Starlight- " But Flurry couldn't get her words out in time before Starlight left. How could Starlight have so little faith in them? In her? Flurry Heart had to do something, and fast.

—-

sorry starlight fans but i can totally see her being like "nah i heavily doubt those guys can be reformed. back in the stone you go."