You are wording his exact point very well, just from a single player pov. Enigma runs a dynamic multiplayer server. So for his “world” to be complete in Falklands, Vietnam, etc, he needs flyable Super Étendards, Harrier I, Pucará, Sea King, F-100, F-105, MiG-17.
Whereas you want those in AI assets and better more believable flight and ground AI, spotting/hiding, ATC, etc.
The point remains: throwing more and more resources at simulating all the detailed systems inside an increasingly harder to make (and thus lower quantity) of flyable modules is not going to help flesh out the world.
You would obviously disagree on number of flyable modules, but I feel like you are both reasoning from a very similar argument and have a very similar vision of what DCS needs.
EDIT: FWIW I enjoy ultra-high fidelity planes a lot. I was the first and loudest one cheering for the Mirage 2000 module when it pioneered highly accurate radar simulation. I loved learning every single subsystem in the Mi-8, every radio, weapons panel and doppler nav feature, etc.
But I also see that a more filled world would allow us to enjoy our incredible systems simulations more. Whether that world is online or single player… and the better and better systems simulation means less resources available to fill that world.