On why you never cut pre-painted metal (or why you should specify T316 SS)

Walked by this sign the other day. I blame the architecture profession that promotes book knowledge over learned-experience.  Anyone with solid experience would know not to use coated metals that were cut after the fact, or why you should use T316 stainless steel for exterior, wet climates.  I've seen something similar with welded joints on galvanized steel.  The subcontractor sold the idea on a youthful architect on this substitution, no doubt.