Dave,
I do nor get it either. I have always been DIYing a lot of my terrain, but especially the last twohas seen a massive amout of inexpensive and good looking terrain, especially from Warbases, 4Ground and Renedra. To the level that I think I will most likely mostball my foamcore and just buy lasercut cut buildings in the future.
The main reasoning behind the thinking for my mates are the rules.
Stuff like FOG has this roll for terrain thing worked into the rules and if it is in the rules it must be the fairest way to arrange things... Right? And the train of thought that replaying historic encounters is boring since you are either forced to make the same mistakes as the historic commanders or that you will only go through the pacs of what historians have said could have been done differently. There are obviously no other choices!
and just setting up a table that is fair for either side no sensible option to create a non-historic battle!
OK... I think I have gone into rant mode!