It's not a matter of people not understanding it--it's that it's just *not fun* when you have to deal with the map changing its layout constantly. Even moreso without free movement in deep space, which has its own un-funness issues.
yes and no, quite a few games have added various physics "features" in the past and the biggest problem is HOW it is implemented . . normally the “budget” has not been there to even attempt a implementation, let alone device a good one. I find the fast paced multi player goal has allot to do with this.
Functional understanding of your environment does not require mathematical or scientific deconstruction. They'll make a few mistakes here and there... and then they'll see the patterns and get it.
There is a good point here . . it was said Homeworld would be too hard for people to play because people did not “understand” 3D . . (funny really) and had the same arguments. Then Homeworld became the benchmark for all space RTS’s . . .
What you need to do is to make the UI simple and intuitive. . so even confusing and unintuitive actions are easy to do . . people will get the hang of it quickly . .
I made a 3D space game as an exercise and all ship movements showed a course plot line . . . unlike normal games this was not just a strait line but because of various physics acting on the ship it ended up being arcs (not to hard to understand) also I allowed final facing to be set (normal in RTS’s now) and some other simple parameters . .
Stop at end of plot - basic move and station keep,
Moving waypoint - keep moving from final heading even if movement orders end,
Intercept target - allows default/optional ranges . . you get the idea, but the “navigator” would have to find a plot that would work.
Orbit target - also allows default/optional ranges (default planet, default combat etc)
This is rather basic and can be added to . . .
These can be combined to make complex movements and if the “navigator” could not find a plot that worked it turned red and you could move the waypoint around till you found something that did work.
Most have been in other more sim games for a long long time . . heck even EVE online uses similar (but basic). . just point and click .
Since autonomy is needed in SINs this could even be more usefull . . set standing orders for ships/fleets . . various patrol, defend, explore - aggressive, stand off, retreat %, etc.
So . . . who needs to KNOW the physics or orbital dynamics?! It will just happen . . ships will try to do what you order, and show you how they will do it, if they can’t it will let you know . . some basic AI can go a long way . . you are a commander you want X fleet there pointing that way at ~ that speed . . “make it SO!”
Easy to learn and use and you learn from watching what physics or orbital dynamics does in space . . .OMG you may learn something!

Now having said that . . personally the scale of SINs (really exaggerated! big sizes / small distances) does not lend it self well to this . .and that is ok . . there may not be a good way to add physics or orbital dynamics to this current frame work and leaving it out is a good move . .BUT that does not mean by nno account that that is the case for ALL games.