I think the main disagreement is about what Civ should really be – a game or a platform.
If it's a game, I rest my case. If it's a platform, well now I'm getting interested.
But why not have both?
Sim City 4 was a platform, So was Civ 4 in a sense. Civ 4 perhaps not so much in the game itself, but rather around it. You can't really put a price tag on Sim City 4, not with dozens, perhaps hundreds of DVDs full of buildings designed by architects and amateurs alike. Wasn't done by Maxis. But the game allowed for it. That's a platform.
The problem with platforms is that you can't sell them for an one-off amount. Or, if you do, you have to up the price. Or you got the way of Maxis. Interestingly, there are examples where people realize this, stuff like MMOs.
What I propose is to have two civs: Civ7 and Civ7 PRO.
One would be a game, the other a platform. With modding, SDK, graphs and the like. Nobody would really care if Civ7 PRO would cost $400, or a 10$ monthly sub, as long as the base game is 50. And I'd gladly pay. Really. If nothing else, to show my respect for someone who is offering me something I want.
What I don't want from 7 is yet-another-game. Worked on and milked until it's more cost-effective to release 8.
Even Civ6 would be a perfectly viable platform. There are enough mechanics already in-game (and the graphics will be adequate for a long, long time) to prolong the lifespan of the game for 5 years or more. It COULD be a platform IF Firaxis would want it to be.
Starcraft I & II are also perfect examples of platforms. Blizzard in general can thank its lucrative business for not making one-off games. Well, at least historically anyway. Talking about SC2... you want better AI? It can ONLY be built for a platform, like Google did for Starcraft II (well, not available for general public, but still).