Removing crystals from squad arena was a phenomenal QOL change and moving crystals out of fleet arena would be as well--at least for me, because I won't speak for anyone else.
We should still have a way to gain the equivalent crystals, but being locked into playing fleet arena at a specific time of day is incredibly inconvenient. Numerous times on these forums there have been threads proposing thoughtful changes that would remove the inconvenience and alleviate the tedium (such as awarding the crystals based on the highest achieved rank within a 24h period, as opposed to the rank in the exact moment, like it is now).
I refuse to believe CG are unaware of this issue--that it is, in fact, an issue for some players--so it simply comes down to their overall plan for how they want players to engage with the game. Clearly, CG are fine with the fleet arena model. We are at their mercy. Nothing here will change until they want it to change.