I don't see why they can't make Arx-earning for exploration be activity-based and not give Arx rewards for selling explo data. That way they could encourage and reward exploration activities with Arx. It wouldn't be hard to decouple the activity from the credits.
Fundamentally, I think FDev need to consider the distinction between what earns Arx and what earns Credits.
I mean, if earning Arx is supposed to be an incentive to play the game, it doesn't necessarily follow that Arx should be awarded on the same basis as Credits.
As Factabulous says (with regard to exploration), if Arx is a reward for
doing exploration then it shouldn't necessarily follow that you receive Arx under the same conditions that you receive Credits.
You've played the game by doing your scans.
Award some Arx for that and then, perhaps, award some more for selling your data - which, again, is playing the game.
By the same token, if you took on a mission to, say, destroy 80 pirates, you might destroy 75 of them and then not be able to complete the mission for some reason.
You'd get paid zero credits (and, maybe, incur some penalty) for failing the mission but I'd
hope you'd still get some Arx for, once again, playing the game.
No idea whether or not this is the case but FDev need to be careful they don't just fall into a routine of handing out Arx along with Credits.