Arguing the benefits of using code to design is like suggesting there are benefits for architects to build full-scale models from piles of bricks and concrete in the back lot. A good architect already understands the materials, and uses that understanding along with creativity to envision something far beyond the building blocks.
Likewise, UX design should be concerned with how the user perceives and experiences the larger product. Getting into the micro aspects of programming when developing a UI with a true macro impact is like building sand castles.
Though fun, far more can be learned by getting out and surveying the landscape, visualizing it and designing models.
The following article argues the opposite position. Though I tried, I may not have fully inoculated you to its persuasive plea to program your designs.