I certainly don't consider it a character flaw if a programmer wants to show me some random chunk of code from a previous employer.
It's not a matter of "character flaws": it's just that it's not legal to copy code in violation of copyright!
Suppose you're the guy in the interview chair. If I tell you how I violated your previous employer's legal rights, why should you think I won't violate yours someday? If I don't have the discression to keep the illegal things I've done quiet, why should you believe that I'm discerning enough to trust with confidential company information? If, during the interview, when I'm putting my best foot forward, I still end up suggesting that I can't be trusted, why on earth should you trust me?
I agree that corporate attitudes are annoying, and I have a firm desire for copyright reform: that's why I write my Member of Parliment, and lobby for change. However, I don't selectively break the aspects of laws that I dislike: and I certainly don't expect a potential employer to be sympathetic if I do.
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AC