Well I understand your frustration BF, but if it goes for me, I would like them to keep bouncing and stuff.
You see, the actual plane explosion when it hits the ground is not satisfying, I've always loved how real planes act when crashing - they don't immidiately break into 1000 smoking pieces, but hits the ground, then bigger parts separate from each other and so on.
As for the AI - AI is AI, it was mostly made to give player a targets to shoot at, of course they could do it better, I dunno, I've been playing lately with Cert's AI mod, I don't remember if there was this bug also, but if you haven't you should try it.
And that stuff you are talking about is nothing compared to what happened to me today.
I was playing on my fun map to test my new effects ( 2 airfields, 100 flak cannons per each ) so yeah when you get close to enemy airfield it gets really hot in the air ( imagine continuous flak explosions from 100 cannons ).
I've been trying plane's strength and then something funky happened. I was flying my Me-262, due to AA fire, my wings broke and my fuselage was falling down. Then when it hit the ground from about 3000 meters, it just kept bouncing and bouncing, and not exploding. I thought, pah, it was a bug.
The same happened with random IL2
Fuselage kept bouncing and was indestructible. Ok, that was just another time. Now I've tried with B29 SilverPlate.
Now I've been flying at 500meters above sea level, and dropped a Fat Man. Everything broke, but my fuselage kept flying and then occasionaly bouncing.
Oh, and I've had all settings on realistic so it wasn't god mode on
So you see, there are a lot of bugs in this game and the AI is not the greatest
I strongly advise you to try the Cert's AI mods if you haven't already.