again, I don't have a problem with copying code - but I as a developer know whether I took enough of someone else's algorithm so that I should mention the original authorship :)
My only problem with circumventing licenses is when people put more restrictive licenses on plagiarized code.
And - I guess - in conclusion, if someone makes a license too free, so that putting a restrictive (commercial) license or patent on plagiarized / derived work, that is also something I don't want to see.