Riot appreciates your concern, and has Mac slated at a (much) later date. They are a small startup company. Their -total- staff (including PR, management, and other non-engineers) is a bit above 50. Compare to Blizzard (which so generously includes Mac support in their games) with an -engineer/developer- staff of 30+ -PER GAME-. This is many times times the raw manpower of Riot. Riot has a list of priorities: Mac is on them, but unfortunately it is not high in the list. This is especially because Bootcamp is a current option.
As for requiring a windows CD, I must confess I am unfamiliar with Macs/Bootcamp personally, but I was under the impression that you didn't need a code. I could easily be wrong, or the person could have been accidentally (or purposefully) pirating it. I don't know.
As for skins vs other things: Riot has engineers, they have artists, they have other staff. Engineers code the goodies, artists draw them. I have a feeling you'd be very upset with the quality of your Mac port if Riot assigned its artists to code it.
Again, I appreciate what you're saying, and understand why Mac users might feel disenfranchised that Riot isn't especially accommodating of them. Please keep in mind that Riot has really limited resources and is doing its best to please the most of its customers at the same time. Right now, the community (including many, many bootcamp users) is demanding other things first. It will get done, but you will have to wait a considerable amount of time for it. Sorry for the inconvenience.