Turns out that is intentional. Community manager EmptyTuxedo confirmed in yesterday's live stream that players are not meant to earn enough credits to compensate the purchase. As to why this is he made two remarkable statements:
The battle bonus is meant to act as a currency sink.
The high amount is supposed to incentivise players to queue up for different fleet queues until the cooldown has expired.
That would be great and all, if T3 was fun to play. It's always been the devs' and/or suits' objective to get players to play multiple fleets. I don't agree with that, but it was okay under the previous tier separations. Now? Veteran (T3) is "below my pay grade", in terms of the level I play at. 3/5 ships that were in my Vet fleet (Vindicta, Koschei, Jutland) aren't available at T3, so why would I want to play T3? It baffles me that I'm being forced away from the part of the game I want to play. Additionally: Why are high-level players being incentivized to descend to lower ranks? That's a recipe for seal-clubbing.
I don't want to be told that I should stop playing my fleet of good ships and go do something less fun. Anyone else remember the maintenance fee?