As far as greatness goes, I agree with you. I would not consider Sarah Hughes or even Evan Lysacek a great skater. Yuna Kim and Mao Asada are both great, and so is Michelle Kwan, among others. We don't know yet how Adelina will do in the future. She is just 17 and only time will tell if she will become great or a flash in the pan.
^ That's how sports work. 100% favourites often fail to win the biggest competitions, which doesn't make them any less of great athletes. Both Michelle and Irina were far better skaters than Tara or Sarah or even Shizuka for that matter. That's why it's not fair to measure athletes by the Olympics only, the Olympics are just one competition among dozens. You have one bad day and it's over for you.
That said, I think Adelina won fair and square. Yuna's program was technically easier and PCS-wise not the best either. I think Adelina should've lost PCS to Mao and Carolina, but not Yuna.
"I hit him with my shoes... if he had given me the medal like I told him to, I wouldn't have had to hit him!" -- 8-year-old Rhoda Penmark in "The Bad Seed"
My take on this subject - a gold medal winner will not have that taken away (except in cases of cheating, doping, etc) - so it does not need to be defended. I think that's a ridiculous idea. You don't have to defend your medal, you already won it. The next competition you compete to win another, or not. It's about repeating not defending, according to what the word means.