From a purely psychological perspective it is an interesting idea. They affiliate themselves with wolves, showing a desire for a close knit family rather than individual expression. They also have a rather rigorous and prohibiting Gemeinschaft, they intentionally ostracize themselves from the rest of society, thus drawing closer to the other member of the 'pack'. Furthermore what is interesting is that they picked werewolves over another group like vampires. This may be for 2 reasons, the first is that a werewolf is part of a pack and has a family, whereas a vampire is a lone survivor who lives at the expense of everyone else. Secondly is that vampires are portrayed as socially savvy and seductive, and elite being that holds great physical and mental power over others. The werewolf represents a feeling of desperate isolation, since they can't control themselves they section themselves off from regular people werewolves are the victims while vampires are the victimizers.
In someways the girl is correct in calling gangs posers while the 'werewolves' are not. Gangs do many similar things such as have their members perform acts that ostracize them from the rest of society and have their primary group be the gang. However a gang uses this for an ulterior motive, in order to remain part of the family, of what is now the only group of people who accept you you have to perform certain tasks for them at regular intervals. Whereas the goal of the werewolves is merely to create a new group around themselves.
Furthermore the notion that they are posers makes me ask what are they posing as? They are not posing as a gang, they are not posing as jocks, and it is clear that they wish their identity to remain as part of their group and not of one like the Goths or Emos.