Well, in Goldbergs defense, a concussion can take anyone out of a fight regardless of age. The difference between Taker/Goldberg and Jericho is he don't take massive couple year breaks or in the Taker's case wrestle every once in a blue moon. Likely at that age you have to accept you aren't you're 20 year old self but if they took care of themselves, and hit the Gym regularly and practiced in a ring to not lose the ability then they could have had a good match.
It was just unfortunate he had a concussion and it was hard for him to work disoriented. Not sure how many of you have ever had a concussion before, but I have. And, they are really debilitating. Even for a trained athlete. So, atleast cut Goldberg some slack on that front. I'm sure he is just as disappointed in himself for it without having people having to rag on him about it.
As for Taker. His final match should have been losing the streak to an up and coming talent that needed a good push. But, WWE and Taker obviously screwed that up.