Maybe I am a bit late to the party with my answer, but I'll share my thoughts on the issue originally posted. I am 100% a civilian, and I find myself fascinated with military subjects. A sim like Steel Beast allows me to indulge and study military stuff I never would have been a part of. I have my "collection" of study sims that never leave my hard drive: Command, Dangerous Waters (naval combat), Falcon BMS and Il-2 (fighter planes), and Steel Beast (armored combat).
I find that on Steel Beast, and the other study sims, the actual systems and weapons and vehicles are a bit daunting at first but soon stop being hard to use; the "switchology" becomes less and less intimidating... the complexity and frustration always comes from not knowing how to deploy and properly use whatever weapon system or vehicle is being modeled. This becomes the long term "hobby" aspect of all my study sims. And it can be very frustrating and/or satisfying. And there are so many questions to find answer to: for example in Steel Beats, am I supposed to have 3 vehicles in a platoon? 4? How do I set up a hull down position? What is the difference between a retreat route and a retreat condition? Of course, I am a civilian, so a lot of the unknowns of being a career military man can become a stumbling block... And sap a lot of the fun, because if I went thru the trouble of learning the proper switches and mechanics of using, say a M1A1, I don't want to be just playing a fantasy world-of-tanks scenario where I just go around blasting evil ruskies... I want to be able to simulate proper procedures and tactics, and use all the skills I developed within the simulation.
Here is where a good study sim vs. a bad study sim can contrast: the good study sim thru a combination of tutorials, campaigns, missions templates, information and atlases, a fellow players community, youtube videos, good AI, tool tips, etc. teach and inform on tactics, procedures, history, deployment; this learning aspect beyond just the "cockpit switches, blinking lights, and bells" maintain my interest. The complexity of the sim is not on the switches/keyboard combos of key presses, but in how you apply your skills using these systems.
The other day I played a scenario I downloaded from this website where a M1A1 platoon has to move towards an objective, capture it, and secure it for a short time. I used (what I think) is proper bound & cover tactics using pairs of M1s... and I was able to achieve the objective with no losses. That was such a sweet moment achieving my objective! It took me months of reading about tank tactics, trying out stuff, watching videos... to finally understand how to properly execute these tactics to be able to fight with my M1 platoon and survive the mission. I wish there where more missions available that taught me this stuff. And more missions that took me by-the-hand and guided me thru the process of learning how to deploy these tactics... The "aha!" moment when I was finally able to deploy my M1s efficiently was priceless and is the reason Steel Beats becomes a hobby.
So to round up my answer: I do not see a problem with Steel Beast becoming more complex in the system/switches and vehicles it offers, the actual complexity found within the simulation is how to properly use them in a "realistic" manner. As a civilian, I love learning how to properly fight within the simulated world. On average I spend maybe 10-15 hours a month "playing" SB, and it takes me 6-8 months where I feel comfortable using whatever system I decide to try. The sim becomes a hobby when I start to study and research the proper way to deploy & maneuver and use the systems simulated on the sim. This is what gives the sim a long life on my hard drive... I keep coming back for more "aha!" moments... anything that SB can do to immerse me on this learning process is highly appreciated.
I had Steel Beats for years, specially version 3... I finally decide this week to upgrade to version 4 and I am sure I'll be using it happily for a long time.