tl;dr: system works fine in populated space with lots of different options to earn ARX, but it disregards the lack of those options when far away from the bubble
I don't care much about ARX. I don't focus on tasks that give me the most ARX - but by simply playing the game, I still reach the weekly cap within a few days.
However, I spend the majority of my time within the bubble and have the option to play other content; I tend to engage in different types of content throughout the week, so chances are much higher to get a good chunk of ARX in those 7 days. Easily. It doesn't require any effort at all.
But I also do at least some sort of exploration near the bubble (mostly on weekends) and it simply doesn't provide as much ARX as other activities - or to be more precise, not at the same rate. And that's important to realize, because that means that other activities provide more ARX/hour overall.
Thus, someone who explores the galaxy outside the bubble and doesn't have any other alternatives has a limited ARX/hour "income". They may invest just as much time as some casual player doing a few missions among other activities within the bubble, but at the end of the session, the "bubble CMDR" will have earned more ARX, while the explorer has earned far less.
So I can understand if some explorers feel like they are missing out on free ARX simply because they decided to leave the bubble.
When inside the bubble or near the bubble with the option to engage in other activities, I think the ARX rewards for the exploration content are ok. But the further away from the bubble, the less alternatives to get ARX, thus exploration is the only activity out there.
So maybe, instead of just increasing exploration ARX one could think about increasing the value proportional to distance from Sol - or something like that.
If you think about it: exploration within/near the bubble isn't really something special, since most systems have been discovered already. But out in the unknown, with zero infrastructure and cut off from civilization for months, I think that could be rewarded with some extra ARX.
Not sure how something like a "distance meter" could be implemented, because people in Colonia are far away, yet have plenty of options to earn ARX easily, just like within the bubble. I really think this requires some more thought in general.
One argument I think is not valid is "it's free, why do you care?", respectively "ARX isn't important, just play the game" - by introducing ARX, FD has created this mess were people suddenly feel like they are missing out. So imho, if you create the problem you better find a good solution.
Either it's a fair system that rewards everyone equally for their in-game activities, no matter how far out they are - or you don't implement a bad system in the first place.
It's like handing out free money at work because people are showing up, but those doing home office - working just as much - just get 10% because "it's free money, why do you care?" or "just keep working, the free money isn't that important".
inb4 "but it's a game, not work!" - yeah, that's not the point. It's about people investing the same amount of time, but not getting the same rewards.