It wouldn't be worth the free shipping. It would be like giving it away for free AND paying to get it to its destination. You have to consider, would you want to do that yourself?
You'll notice a lot of people put in their listings (such as I have), no gin or no lower days. Sometimes a lot of us have reasons why our listings are that long. In my case, I try to time my listings to match payday so that I can keep my good record of fast shipping. Also, doing GINs cost points, which some members do not want to part with, especially when the person requesting does not even use the GIN after all the begging. These are some things you may want to keep an eye out for in other auctions and when you start to get more seasoned, it will dawn on you why some people get a little disturbed. If you ever have any other questions, you can go ahead and inbox me and I'll try to help out.