Suppose I invented a label for some games: "wealth dice games". These are defined as games where the goal is to find or retrieve symbolic wealth, and that use dice rolls as part of their game mechanics.
Suppose other people join me in using the label "wealth dice games" for this type of game we love so much. We start calling ourselves "wealth dice gamers" and form a little club that promotes the playing of wealth dice games. We start to grow.
Of course, there are many people who play games who are not officially wealth dice gamers. Many, many more, in fact. They outnumber us about a thousand to one. However, we grow fast enough and we're loud enough, talking about our hobby, that these other gamers notice us.
Suppose also that I and my little clique don't tell anyone what the definition of a wealth dice game is. It's a really simple definition, but we keep it a secret, specifically because we have a grudge against other, much more popular games that we want to exclude. Monopoly involves both dice and collecting wealth, so it should be a wealth dice game; but we have a grudge against Monopoly, so we tell members of our club that they aren't true members of the WDG if they play Monopoly.
This, of course, hurts Monopoly. Millions of people play Monopoly, but by being so elitist, we are denying Monopoly gamers the chance to increase their ranks by less than one percent. An outrage! It's all because if we admitted that Monopoly was a wealth dice game and allowed other wealth dice gamers to play it, they would see that it's a fun game and would stop playing lesser, non-Monopoly games. We're jealous and spiteful.
* * *
This, of course, is exactly what a certain small but vocal group of D&D 4e players think is going on with the OSR. They think that the OSR is a club, that "old school" has some kind of precise definition based on simple thematic ("dungeon-crawling") and mechanical ("class, level, and hit points") criteria. And the OSR is deliberately excluding 4e players, who vastly outnumber old school gamers, from their little club, which is TOTALLY UNFAIR.
See this comment in a troll thread, for example:
I don't think 4th Edition fans care about being "part of the OSR". They ought to be welcomed if they want to be, though.
Dungeon World is awesome and old-schoolers should embrace it. Hair splitting over whether a game with hit points, gelatinous cubes, dungeon delving and casting Charm Person on a formian is or isn't "old school" or part of the OSR is inane.(Emphasis added.)