I am fine with the word, but agree that it often times used in situations where it's unnecessary. This is usually the case in discussions about privilege, and when the topic doesn't specifically involve gender identity I think it's silly to tack "cis" onto the long list of adjectives that describe privilege. White, straight male is concise enough. There are plenty of other disenfranchised groups usually not used in these lists that have just as many disadvantages in life as trans people do, and in some cases there are more of them. Dwarves, people with mental/emotional illnesses, poor people, deformed/disfigured people (burn victims, amputees, etc.), handicapped people... the list goes on.
I'd rather cis be used when the situation calls for it, not for use in an arbitrary list of privilege perquisites.