The game was designed from the ground up around the grand strategy concept of having to decide where to allocate your available units across your offensive and defensive fronts. That's one of the reasons I love the game. It would be far too easy, and grindy, if there were no ship caps. It might be amusing to play that way once or twice, but then again thats what the cheats are for in the first place. =)
If you want a game that is meant to be played that way, I suggest Total Annihilation. That classic game also has an economy based around resource inflows and outflows similar to AI war, but with no caps on anything. The units are also appropriately balanced around that type of gameplay, and there are a ton of fun mods for it too. =)