Does this make sense?

So I'm looking at USB 5.1 adapters (for those who don't know, they plug into the USB port of a computer and let you use a 5.1 computer speaker set), and I've finally found one that looks pretty good (actually it's just the only one I've found). Reviews are nice, and you can even plug in microphones and things of that nature. It even has Mac support. But oh wait, the Mac version of the software only has support for two channel audio. Does that make sense? Wouldn't that defeat the purpose of buying it or even giving it Mac support? I had to read that little bit a few times over just to make sure I was reading it right. It also states that performance is best under Windows XP. I wouldn't have guessed that, since it can't fucking do what it was made for on Mac. I might have to call this company's tech support tomorrow just to make sure that wasn't a typo.