The example below, where John Gruber was accusing Google of copying Apple is a good illustration of why I think “copying” software is more of a good thing than bad.
In coming up with a 3 column layout, Apple seems to have ‘borrowed’ an idea from Microsoft. Apple also seems to have borrowed showing email as conversations from Gmail. Gmail borrowed the 3 column layout from someone, since both MS and Apple are already using it. And for all I know, other email programs already had features that appear in Gmail and Outlook and Apple Mail.
I don’t see how anyone was hurt by any of this - and since both Gmail and Apple Mail were made better by their borrowing, users are better off.
And if you are really against copying software, you should be just as upset with Apple as you are with Google.