If we were taking 'climate' literally, you would probably be right. But in Simutrans, climate means region as well, each region coming with a different style.
As an example, I attached how my latest mediterran houses look with the current cobblestone road and the current sidewalk. While both road and sidewalk probably exist like that somewhere in a mediterran country, they certainly don't go well with the style for the houses. I'd like to change the sidewalk* pattern completely for the pattern on the base of the houses, and exchange the cobblestone pattern for something in a warmer gray, perheps a bit lighter. It's worse in the desert area, which is even more stylized.
Now I don't think most paksets would profit much from this. Older paksets don't even utilize climates all that well, regional paksets for single countries might not have much difference between the climates. Nevertheless, it feels like one of these missing features. You know - sure you can create climates, and define precisely what spawns in them - except for the roads, sidewalks and bridges, they are always the same.
*Yes, this is about roads, not sidewalks. Sidewalks can be integrated in the road anyway, so no point in requesting them seperately