Wrong is not the correct word in my opinion.
Everyone has his/her way to reach the top, or at least try. And rbarta: Using yaks and porters to get your stuff to the mountain, is not the part where you are climbing the mountain itsself actually. I am aware you can look at it in many different ways, but why make it so complex and vague, rather Keep It Simple.
My two cents about oxygen: I've never been above 6000meters(18000ft), so I cant tell exactly how it feels up that high. but what i do know is this: Climbing somewhere with oxygen feed = a lot easier then without. Regardless of the few extra kg's you might be carrying. While I climbed cotopaxi, I met the fact: thin air, low amount of oxygen. And I am pretty sure it would have been a lot easier to climb with oxygen. 2-3 kg's extra = nothing compared the amount of extra oxygen you receive from it.
But back on topic: I consider it cheating, or at least dangerous. Why dangerous? because people who are actually not capable of going that high, do go that high. Failure in your system would possibly kill you. While if you climb without, there is one less thing which can fail you. And your body is in general pretty clear about what it can take and what not. With oxygen you loose that contact with your body feeling.
Carrying oxygen with you incase of emergency(and that means you have to go down, not an emergency to still reach the top!) might be a good thing.
A fair climb... is when you find it fair yourself... it is hard to say when it is cheating or not on most parts of the climb. Some might say using sherpa's is cheating, or using ladders etc.