...If you were attacked by someone would you really care about how the knife feels or looks or functions?...
Yes. It doesn't matter what the situation is; It is important to me that my knives feel right and function well no matter what the task. I would have difficulty keeping a knife if it didn't feel right in the hand.
...A cheap 20$ walmart knife would do just as good in self defense as a 100$ knife...
Heaven forbid I am ever in a situation where I would have to defend myself using a knife. All else being equal, I would have more confidence in a $100 knife versus a $20 knife in performing any task. I have purchased cheap knives in the past and it has been my experience that generally, you will get better performance if you spend a little more.
...Human or animal skin is not that hard to cut through...
I dissected a cat while in college. It's skin was plenty tough, but maybe my scalpel was just dull.
...Camping, whittling, throwing, now that is where you need a good strong knife!
I agree. I like to have a good strong knife in all situations.