Realistic? There's lots in this game that's not "realistic" to the way things were in WWII, or real life in general for that matter. If this game were truely realistic most of the players here wouldn't even be able to get their planes off the ground, much less bomb anything.
If taking out radar for the entire country bugs you, then consider that in WWII most areas, countries didn't even have radar. Be glad we even have it. Actually, the radar is HT's way of making the game more playable. In the real world, every single base would have people stationed at them, in the game we don't have enough people to do that, so we need a mechanism to keep track of what's happenening so we can at least respond and make the game playable. Otherwise, we'd lose fields left and right to raids we never had a clue was coming, or fields that we never even knew were being attacked.