"Noob question, why the matte vs glossy SS finish?"
My understanding is that there are two main ways to increase the corrosion resistance of stainless steel during the finishing process. One is by pickling and/or passivation in acid. The other method is by electropolishing. Electropolishing is an additional step which increases the cost to manufacture.
The Vertical Evolution hanger appears to have been tumbled to remove burrs and soften edges, then pickled, passivated, or both, to remove iron contamination and provide a fresh layer of chromium oxide protection. That leaves a dull, matte finish.
The Lappas hanger appears to be electropolished, resulting in a shiny finish. The HowNot2 page reads: "The product undergoes a passivation process (marine version), for the purpose of the removal of free iron or other foreign material. In addition, it is subject to an extra process of polishing-finishing to maximize corrosion resistance."