it's just a generic dismissal, a way of putting someone in a box without actually engaging with anything they say. which lumps it in with 90% of all internet arguments really. "Your argument must be invalid because you're the type of person whose arguments are invalid."
my account is 11 months old, which invalidates your theory that i'm part of some recent influx. also is septemberism still a thing? i thought that went away when most people had home internet rather than getting it through a university.