Few dozen or few hundred? This isn't the 90s, games are played by millions of people daily. More than tens of thousands of people are effected by someone taking down, say, LoL servers with a DDoS.
you're forgetting that a lot of games use the individual server model. for example battlefield 4 has 70 player max on any given server. meaning a DDOS will only cause problems for that many
In those cases, there is usually a non-player server that can be targeted.. Also, there is absolutely nothing stopping this kind of attack from hitting multiple servers; the only limit is the total bandwidth.
