Well I can't say I completely disagree with what your saying, but I'll play devil's advocate...
Being the hunter, I wouldn't want a dead / smoking gv giving away where I killed the last enemy vehicle.
That may be, but this also adds a touch of realism to the game. After all, if a tank rolled over a hill in WWII and saw twenty of his buddies all sitting there dead....something tells me he's not about to go charging in there guns ablazing.
Also, if I'm camping main gv hangar, then I wouldn't want the next person that spawned hiding inside a dead gv.
I think that's why they suggested the base not accumulate the hulks.
Also, if I kill you in your spawn, how are you supposed to respawn in the same spot (hangar) if your dead buddy or your previous vehicle is still sitting in the spawn point?
I was under the impression that spawn points were randomized to an extent. And for that matter, how realistic is spawning anyway? Sometimes one must suspend disbelief.
All in all, I think it would be a good addition if done in the proper way.