Another reason why there's a compressed ground scale is that it speeds up the game, but not because it allows movement without getting shot at. Instead, it means players don't waste time standing there shooting at each other at extreme ranges hoping for 6s and 10s on all their dice.
I played Vor, a scifigame that had very good weapon ranges, the basic infantry rifle fired accross at least 36" of table space at long range. Now that really bogged down the game in shooty battles.
Sure you can make the argument for more terrain, but then that just defeats the argument because why have that extra range if terrain just blocks it? It just means units funnel into the few passages to get closer to the enemy.
Also, the ranges in game help to emphasize the difference between infantry, special weapon, and vehicle combats. Where infantry get in to firefights around 24" away, vehicles and other special weapons engage at 34"-80".
BFE is certainly plausible enough for being a game. Remember that the focus of BFE is to be a game, not a simulation. You're statement that every wargame is also a simulation is only partially true. Wargames of all kinds strive to be different levels of game to simulation ratio, BFE ends up more on the game side. If it's that big of an issue there are other modern games out there, or you could play with 15mm-20mm figures.
The weapon ranges as they are now work as a game mechanic, and are certainly not as limiting as say Warmachine and Warhammer's ridiculously short ranges.