Social games like Mafia/Werewolf and Resistance have been around for a few years, and they're here to stay. With further development of these games with activities like 2 Rooms and a Boom, social games are making an impact. But are they really games?
I think the answer is "it depends on the people." I know that's not a satisfying answer, but it really is true. Some people will consider them games, and some people won't. Personally, I think they're both games, but they're different than games like Catan, Ticket to Ride, or Small World. Mafia and Resistance both fall into the "group think" mentality, meaning that a group starts having expectations for the way loyal people should behave in the game, and anyone who does something different is under heavy suspicion. These types of games often require people to have good poker faces, and learn to lie well in game. I'm not saying that you should learn to lie well to people, but I will say that what happens in these sorts of games needs to stay in the game.
Observation and an ability to read people is crucial in social games. Everything that someone does or doesn't do can give a little clue about them. That's the main reason that I love Resistance: Avalon. It's one gigantic puzzle that everyone is trying to figure out, where most people will get close, but it's hard to get perfect. There's a lot of discussion, and sometimes it's impossible to know for sure. That's where you just take a guess and go for it.
Social games may not be games in the eyes of some people, but they are often a lot of fun. I've spent a lot of hours playing Avalon and Mafia/Werewolf, and most of them have been a blast. That being said, these games aren't for everyone. You really have to be involved in the game, and when you're not, it's hard to have a good time.
TL:DR - Social games are games. They're not for everyone, but with the right group, they're a blast.