An interesting article from Greg Costikyan on "grognard capure":
All game styles run the risk of what I term 'grognard capture.'
'Grognard' was a slang term for members of Napoleon's Old Guard. Hardcore board wargamers adopted it as a term for themselves. By extention, grognard capture means capture of a game style by the hardest-core and most experienced players--to the ultimate exclusion of others.
The most extreme example I can think of is what happened to the Squad Leader series. Originally a relatively simple, accessible game of infantry combat in World War II, the publishers released supplement after supplement, each with new rules adding to the complexity of the game. Finally, they revamped it as 'Advanced Squad Leader,' publishing it in a loose-leaf binder so you could insert new rules as they were published, with systems as obscure and silly as the 'Sewer Emergence Table' and the 'Kindling Availability Table.'
I can think of other examples of 'grognard capture'. Card-driven wargames for example - compare the simplicity of We the People with the exception-fest that is Barbarossa to Berlin.