Why do mac users need 10.6 (4yrs old) while PCs can use winxp (11 yrs old) iTunes 11

[chupacabra31]

So if you have mac you have gotta have a minimum of OS 10.6 (4 years old) which it clearly states on the box, however if you have PC its A okay to have an 11 year old OS soon to be 12?

I understand that OX 10.6 is only a $20 upgrade and for me it is no big deal. I hear a lot of outrage though from others such as I just bought this dang iphone 5 or ipad mini and paid a premium for it and now I gotta spend $20 more to use it with my mac?

Again if your being harsh you could say "Well did you read the box?"

Just wondering what apples official positioning or your best positioning as to the reason for this would be?