I got my kitten from a breeder, she's a Himalayan so of course she's never been outside, and she shows absolutely no interest in it. We left the deck door open with the screen door closed, she looked outside and returned back to her normal play.
Now I've raised kittens born in the wild and they're the exact opposite, they get a whiff of the outdoors and that's the only place they seem content.
I don't know if it's "science" but I think they are just so impressionable in those first few weeks of life, that whatever they get used to is what they'll always love.
Kitties are funny