I think really FCs have been a real albatross for FD. They've taken many, many iterations to get to us, and are one of two light patches in a giant lull in updates. Its pure bad luck for them and triggers people when something which is intended for loaded players appears now in the void. But they could not be swapped for something else more universal as that would be more delay.
Well, true, but this is only true due to the way FDev designed the fleet carrier feature.
They could have easily made carriers more useable by:
1. Offering a few sizes of carriers with varying prices, upkeep costs, and capabilities.
2. Including player controlled mission boards on the carriers.
3. Including UC as an option for the carriers.
4. Implementing player to player material trading on carriers.
It was a design choice by FDev to make them as exclusive as they did. They certainly didn't need to.