I'm not so sure about this, I look at Classic WoW, a huge success, as reaching out to 'hardcore fans'.
I think that actually supports my contention.
The contention made was the following:
Hardcore fans/Grognards are the engine the powers an IP, if you make the engine happy you can let it do the work for you.
I would strongly suggest they are
part of the engine, but not the core of the engine, let alone the engine itself.
Also, if we're talking Classic WoW, let's be very clear - that hard disproves the idea that you can say "Hardcore fans/Grognards". It shows it is definitely not true to regard those two groups as the same thing or massively overlapping. The majority of Classic players are not grognards in WoW (or generally). They're not, contrary to expectations, old returning WoW players who miss the good old days. That was true when Classic first opened up, but it didn't last.
Instead, they're most high-strung (arguably toxic) hardcore players, the players most obsessed with "challenge" and "status" and so on (outside the Race-For-World-First raiding guilds and similar - though there is overlap with them). Most of them apparently started at some point between Mists of Pandaria and Legion or even later - some are even new to WoW with Classic WoW. It's actually surprisingly rare to find people who play Classic significantly who were around in Vanilla, where in Retail, it's relatively common to find such people.
Do they tend to be more hardcore? Absolutely. The Classic server players strongly tend to be more hardcore in that they spend more time in-game, spend more time researching the game, have strong opinions about the game and other players and so on.
Is Classic WoW valuable? Yes, on multiple levels, but particularly because it attracts a different group of players to WoW and gives them something to do. But it's not the grogs, ironic as that might be. The grogs generally had their fill of Vanilla and after playing it a little on Classic are quickly reminded of everything they hated (or play it enough to bask in nostalgia, but then they're full up on that, because they don't have the friends/guilds etc. that made Vanilla special), so they go back to Retail.
It's a money-maker for sure, and is hardcore-oriented, but it's not grog-oriented (in practice, as much as it might seem that way in theory).
I realise there are a lot of factors at play but movie franchises and comics prove you wrong.
No, they do not. Which movies have succeeded by focusing on "hardcore" audiences rather than the large audiences?
Comics are a fundamentally niche deal at this point - they don't have a non-hardcore audience. They used to have a casual audience, but shed for various reasons, and now constantly flirt with bankruptcy or failure.