Well, scammed is not really the word. More like they did no research into what the cost would be for two tickets not using this coupon and maybe paid $9 more. At the end of the day it's $9
Do you shop at Wal-Mart etc., and not look at the price then announce a scam when it fails to meet your expected price?
I think quite a few 2 for 1 or companion certificates at other airlines limit the use to a high-ish fare for person A to use the coupon for person B. Simple analysis will find out if it's worth it or it isn't.