Maybe cost is the reason. But I wasn't sure why AL needed any coating to begin with. I defer to someone with more metal experience.
Aluminum oxidizes (rusts) just like steel does, just differently. Bare aluminum will also discolor quickly and look nasty. Anodizing prevents this and adds a clear-ish colored coating. Powder coating is a lot different. I am guessing since they already get other parts, like the steel skids, powder coated, getting these skids powder coated is pretty easy for them.
I'll run those steel ones with pride, I have no shame. These new ones sure are nice though!
