I'm not an evolutionary biologist, but it seems to me shame is a useful tool that many today feel should be banished by force. I believe that any trait that is as embedded into the psyche is the product of millions of years of evolution and we do away with it at our peril (it is apparent that chimps and other animals feel shame, for godsakes).

Yes, you can broach subjects such as society's former abhorrence of homosexuality and say that nobody should've ever been shamed for it, but isn't it possible that homosexuality became "acceptable" to society when society was evolved enough to accept it? When I was younger, one felt shame if one's parents had to use food stamps to buy food. If you were seen at the grocery store by a schoolmate you might get ridiculed at school. What good that did isn't open to debate: my father and mother both worked as hard as they could to get off assistance as soon as they could (and they did), and I grew up knowing that I sure as hell wasn't going to allow myself to get into that position. I'm unable to tell how much that has motivated me. But now we give out cards that look like credit cards; no shame to be had at the grocery check-out line, and so there's less motivation to do something about it. This sort of thing is not good on the whole; people must be self-sufficient and self-responsible or the whole system breaks down (unless, of course, you're a socialist, and if you haven't learned that lesson over the last 100 years, I don't know what to tell you).

Yes, shame can be painful. So what? It's one tool; sometimes tools are misused and can result in injury, but on the whole tools are necessary for growth and improvement and do much more good than bad.