Of course, many actors don't pretend to experience emotions, they actually make themselves feel the emotions they're supposed to.
There's a lovely moment in an behind-the-scenes thing for the sitcom Derek in which Karl Pilkington (who had never acted before being in the series) was saying that he wasn't a proper actor. He said that rather than pretending to experience the emotions, he just pretended that what was happening was real. Then he references a scene in which he has to shout at a woman whose mother has just died, but who had never cared for her mother. After the scene he had to avoid the other actor and said he was physically shaking because he was so furious.
The rest of the cast laugh at him and tell him that that's what acting is.
Is it something that's particularly admirable? Not more so than most other jobs, I'd have thought. But it is a skill, and a difficult one to do well.