After reading all the comments on this thread I must say:
It's funny that GW gets so much crap for its rule writing ability, yet, reading many of these comments just proves how terrible most people would be at balancing the game themselves.
Person 1 - "This isn't fair, my army can't do this, so rules should be changed!!!"
Person 2 - "Yeah, but your army can do other things, and gets benefits it other areas"
Person 1 - "La, la, la, la, not listening"
Seriously folks, that's all we need, for vehicles to be even tougher to take out.
Do, you have any idea how much it can suck playing Daemons? Land Raiders and AV13 Walkers can be an absolute pain, and can literally decide a game.
Plus, when you logically think about it, why can a monstrous creature not take out squads and vehicles?
Think of the size of Trygons or Swarmlords, or the power of Daemon Princes. They can reduce entire armies to pulp, yet in alot of ways they are incredibly fragile. If anything MC's need some buffs, not penalties.
For example, why can a hidden powerfist or claw constantly pop away at a MC, but he can't decide, "Hmmm, maybe I should kill that guy first".
And, for f*ck sake, don't get me started about how hidden powerfists/klaws/Force Sword can instant gib an expensive HQ unit.
"We are Kharn the Betrayer, Lucius the Eternal, Typhus Herald of Nurgle, Fabius Bile, Huron Blackheart, veterans of a million campaigns, scourges of the Imperium, we cost the same amount as a single Troop Choice or Vehicle, and in some cases even more .... oh, we have just been splatted by captain no-name and his f*cking uber fist.
No wonder we can't break out of Cadia.
Well, at least Abaddon the Despoiler will lead us to victory, he has the blessings of the four God's of Chaos and is immune to Instant Death ... oh for f*ck sake ... he's fallen on his fricken sword again!
Back to the Eye lads, back to the Eye."