as much an art as it is a science ,这里的much后面为什么可以加可数名词

Something is as much an art as it is a science.
与其说...是门科学,不如说它是门艺术.
或
虽然...是门科学,但它更像是门艺术.
as much as 修饰 "is",表示程度.
这个句子也可以调整为更容易理解的形式:
Something is an art as much as it is a science.