This is a random system I picked and scanned for usability. The green carriers are usable in any way. The red carriers either have all systems suspended or are locked to prevent docking.
~60 carriers are completely unusable, with ~30 available for docking and offering basic services. It is not acceptable that fleet carriers are cluttering the galaxy when ~2/3rds of them are completely useless. And even the ones that are potentially functional, a whopping 100% had some or all of their advanced services disabled.
1. Upkeep.
Clearly, the cost of upkeep is prohibitive to keeping them active, but not to keeping the fleet carrier. None of these carriers are in danger of running out of funds, and are unlikely to disappear anytime soon. However, because upkeep exists, they instead disable all their services to reduce it, and become a permanent and useless waste of space in the galaxy. Upkeep is punishing the people who want to help others, while rewarding those who make their carriers completely useless.
2. Clutter
Most of these carriers haven't moved in weeks or months, and if at some point this system became full, it would likely stay this way for weeks to months, as well. There is no system to keep fleet carriers moving, spread apart, or keep systems from filling up. This can vary from annoying at least, to crippling at worst in special cases like Rakham's Peak.
Additionally, why on earth can players see fleet carriers they cannot interact with? Why can I see squadron or personal-only carriers? They do literally nothing but clutter up the game.
3. Discouraging player investment.
Most of these carriers do not carry more than basic services. This makes it clear that most players see the basic FC as the final model, with additional services as a waste of either space or credits.
Fleet carriers were supposed to be a great thing for the game. Instead they've become a huge waste of space and clutter in the galaxy.
Anyway, this isn't a suggestion, just a list of my complaints. Make of it what you will, but it'd be nice if something were done about the mess that is fleet carriers.