It is fair. As you are well aware, alcoholics wreak havoc on many people's lives. Your family has every right to invite whomever they choose into their home. Likewise, they have every right to bar whomever they please. And you have every right to attend or not. This situation is directly a result of your husband's actions. His actions = his consequences.
My alcoholic boyfriend had seven months of sobriety but then decided to "have just one more drink to see if he could handle it now." That resulted in one final binge that ended his life. After what I've been through, six months of sobriety doesn't convince me that an alcoholic is embarking on a life-long change. Six months of sobriety after 40 years of drinking was a drop in the bucket for my alcoholic boyfriend, and was barely any time at all in comparision to his drinking career.
You can't blame your family for wanting to protect themselves from someone who has been harmful to them and harmful to you. Either go without your husband or don't go at all. But it's wrong to be angry at people who have set boundaries in their lives to protect themselves from harm.