That is very easy to explain: Plot Armour. We wan't pretty explosion in our sci fi tv shows so when some fireworks are needed then the most convenient ship goes kaboom.

The reason carriers are not nearly as powerful as thier naval counterparts is a combination of two main factors.

1. Naval ships sink. Poking a hole into a naval ship is pretty easy with modern technology. One bomber could easily sink many carriers and carriers carry many bombers. Once a ship sinks below the water its gone for good and can't affect combat anymore. In space this is different. If you poke a hole in a properly designed spaceship then whatever compartment you punctured farts its contents into space and not much else happens. To have the same destructive effect you have to pretty much cut the ship in half or explode its reactor in some cheesy fashion. Look at the weapons on TEC bombers and think about how many direct hits it would take to cut a Marza Dreadnaught in half. That amount of ordnance wouldn't even fit inside the bombers!

2. Secondly space is BIG. Aircraft on earth can fly many miles, blow something up, turn around and fly home. In space this is far more difficult because the distances traveled are immense. Adding to the problem is newtonian physics. Exactly half of all energy spent to move in space is spent just slowing down. Its not possible to simply pull a U turn. If you spent X energy getting up to whatever speed you are at. You need to spend exactly twice that to turn around and go home at the same speed.

Of course neither of those issues are very important in a computer game but its a good thing to consider.

like stated many times already,  the game has to be balanced,   carrier still are to powerfull currently....  just try making carriers only in a multiplayer game, and move them away when enemy get's close, so happy that in 1.1 carriers will be made super-expensive..... as they should be,   but the problem might still remain :/

as for naval tactics,   theres no way you can compare naval warfare to space warfare,

You also seem to assume that humans/Vasari will be aiming. In that time period, the absolute most that an organic is going to be doing is designating targets. If they haven't yet figured out to let the computer decide when and where to shoot, they deserve to lose the war.

Don't forget about the size of the ships involved in Sins though -- sure, they may be moving fast and in three dimensions, but even a frigate is large enough that it can't generate a miss very easily, becuase its accelleration is relatively low.

Almost never.  You're asking for a quick death if you're a submarine near the surface.  A sub's saving grace is stealth and that's only accomplished by running quiet and running deep.  The only time a sub should be at the surface while in transit is for however long it takes to suck more air and then it's time to submerge again.

Several things wrong with this idea. First, WWII is not MODERN. Carriers may still be the most important ship, but guided missiles now dominate modern naval planning. Also, battleships were not useless in WWII. If the Japanese had used their battleships when we had those 3 carriers, Midway would have been irrevalent. It took 17 bomb and 20 torpedo hits to sink Musashi at the battle of Leyte gulf. If they were willing to risk them early in the war, the US wouldn't have had the air power to sink them.

Second, exactly how effective force fields are, if they are ever invented, will define how space warfare is fought. If they are really good, strikecraft will be rendered useless as you'll need bigger sized vessels to store the weapons required to destroy them. If they are not, then carriers will keep their place as the most important vessel in warfare. Of course, as no one has any idea how these will work, sins can basically do whatever it wants with the combat system.