I've heard this repeated ad nauseum (not just in this thread) and I think it's total crap. You cannot tell me that if you spend dozens of hours writing something then someone comes along and goes line by line telling you how what you wrote is an abomination that you're not going to have an emotional response.
If that's the case it has to go the other way as well. Just finish writing a new process that will save the company $30k a month? Doesn't matter. If your code doesn't have anything to do with you then it's not an accomplishment to write good code (I don't believe this).
Just to be clear, I do think code is personal but I do think people should welcome any constructive feedback, particularly the negative. Yes I feel a twinge in my ego any time someone criticizes my code, even minor stuff; but guess what? When they look at it next time they won't be able to make the same criticism, because I will have fixed it.