I think it's an analogy, not a comparison. "Eternal September" being a time when there is a ceaseless influx of those who are unaware / uncaring of the rules.
Using "elitist" as an insult is getting old. You have to accept that behaviour shown by uneducated people is often inadequate. (Of course, "uneducated" about what... that depends on the context. We're discussing netiquette here but it could be anything else.)
sorry, maybe 'snob' is a better word to describe folks who cannot handle the unwashed masses invading their domain. But in seriousness, I understand the impact a bunch of oblivious (willfully or otherwise) people can have on a here-to carefully curated and managed space, I sympathize.
Well it depends on the 'place'. Complaining about the common folk using USENET? yes, that's snobbery. Complaining about too many people messing up a natural space? No, that's not snobbery.