I made a topic about this some time ago, Alex didn't like it, because ships, already have weak points as it is now, so why make those weak points even weaker? its a spaceship after all, not a tank.
Well I don't think that argument really works. Even in the analogy- Why would you NOT design a spaceship after a tank especially one meant for battle?
Even if you decided to make a pure exploration vehicle you would run into issue BY DESIGN that would create weak points if you did not reinforce the amour e.g airlocks, engines, fore of vehicle, and so on. Alright so maybe that's why ships have equal armor all around right- they simply have perfectly balanced everything? Well I guess although once you are designing something you might want to take into account what you are designing.
Lets look at the conquest or the onslaught - if you have, by design, a side of the ship that you have to turn toward the enemy and is the most likely to be hit. Why would you not armor that side of the ship?
Look at this in terms of game play- a player in an onslaught is encouraged in combat to turn toward his engines in order to not take armor damage on the front. The question is why not simply have that armor in the front in order to encourage onslaught use as an onslaught. Remember it is a forward facing tank not a pirouetting conquest.
I personally do not particularly enjoy the way the current system works. Currently most forward facing ships, such as the hammerhead and enforcer, punish you for playing them as they should be played. You either wither lose all your forward armor or need to turn (painfully slowly).
The way this plays out feels very artificial and takes away from the way the game plays.
[edit] I suppose one could point to modern ships which have relatively thin armor when compared to their WWII era counterparts. This was due to the creation of the shaped charge, with it's armor penetrating abilities (20+ ft of steel), and missile based combat. The shaped charge makes it very expensive to kit out a full battle ship (although not a tank) and missile based combat means that it is not worthwhile, and counter effective, as mobility/agility/stealth/range are a more effective means of damage reduction.
Well from a gameplay perspective this type of combat isn't all that much fun. And, not how it goes down - we know where most of the damage is taken, battle to battle, and the weapons do not punch through armor in one hit. Take for example the onslaught the engine section can take just as much armor damage as the sides - even though it is less likely to be hit. This is a waste of resources and means that if you engage in combat again, in quick succession, guess which is only part of your ship to have alot of armor left. For pretty similar reasons I don't think it would make much sense lore-wise either.