Luisa's just doesn't seem that good to me, even though it repeatedly came in high on "top pizza in Charlotte" surveys over the past years.
Their selection of toppings is, in my opinion, limited: maybe toppings like green olives are unusual, but jalapeos are not, and Luisa's has neither. To me the pizza tastes pretty run of the mill. I wasn't even struck that the toppings are particularly fresh, and the thin crust was actually quite soggy for me the last time I ate there.
To top it off they seem to close kind of early, especially for a pizza place. I could maybe see giving the pizza three stars as it's completely "average" (at best), but after the missing toppings, the crappy hours are enough to put Luisa's in two star territory.