I am all for game rules - any type of game rules - to be designed as simply as possible to get across the desired result. Indeed, it is the mark of a good set of rules to have a clear design focus and not add any extraneous details that detract from efficient, edifying and pleasurable play. But I do think that the complexities of warfare and the military systems that societies construct to wage war demands some attention in war-games design. I also think that players should apply some effort to learn those games to make the games we play a little more than a rather dubious entertainment.
This is a delicate balance. Taken too seriously, I think this hobby disrespects the horrible price people have paid in war. Taken too lightly, however, we do the same thing and learn nothing from the process. Wargaming can teach us things while being challenged by the "game." They are studies in this violent human activity whose systems have been supported by huge effort and resources. Trying to figure out how these systems worked has occupied military historians and game designers for a very long time and, as Phil Sabin has asserted, war-gaming can be a useful tool to explore these realities.
The effort to represent warfare, or limited aspects of it, on a game table demands some careful consideration. While war reduced to its most basic purpose on the battlefield has commonalities across time, the military systems that have developed for both practical and socio-cultural reasons are less generic. Romans did not function like Classical Greeks or Celts. Zulus operated differently than British. Germans applied different doctrines in WWI than those of the Canadians. Representing these differences has some importance.
For these reasons I come to my concern about the popularity of very simple and generic rule systems that seem to rely on simply repackaging the same rules in different clothes and calling it a game set in particular historical context. Mechanics can and should always be as simple as possible, but rules that really differentiate armies across time need more attention. I also think they make games more interesting.
Funnily enough, many of these simple and generic games are skirmish games. I do not like skirmish games because I find that they are either too simple and reduce to absurdity the even greater complexities of warfare down to the personal level (that must still account for the doctrines and systems). Or they are too complex, trying to represent 'everything' and making it impossible to play.
Now, I have not right to say what others should play. But I do think that this hobby has much more to offer than 'bang-you're-dead.' With a bit of effort we can be engaged and learn something.
I'll stop now. :)