[She has a point, since she'd woken him up in the middle of a nap in the stables yesterday. This is different though. Maybe. Just a little.]
The stables are an inclosure and protect from weather and other elements.
[But more importantly.]
As nice as the Butterfly Pavilion is, it doesn't really offer the same amenities as the stables do. I have shelter and a blanket when I'm there if needed.