I tried to employ that logic but my synapses wouldn't let me. I think it's the artificiality of arx, from an in-universe perspective. It just serves to amplify the idea that this is something I can only interact with if I've got some arbitrarily-named tokens that I've bought using 21st century currency.I feel the "BUY STUFF NOW" button in the HUD actually adds to the immersion. Or do you all think that in 3305 AD interfaces are so blissfully free of any commercials? I mean, it's the 21st century and I for one can't scroll one page on my phone without running into three ads for whatever the thing du jour is today; we have ads inside the Start menu in Windows 10 (for those of us still using the M$ OS), and there are ads inside your Smart TV menus and ATMs and so on. It's just another "I NEED YOUR ATTENTION HERE - SPEND MONEY NOW" button for me.
It would be a different story if the store was using in-game credits, but we all know the list of reasons why that's not a viable option. The game already has in-game advertising for ship manufacturers, but the difference is that you can buy their stuff with in-game currency.
I guess if you intend to only ever earn arx in-game, and never buy them, it might be possible to headcanon them into some alternate medium of exchange to credits. A sort of FOREX currency that for some reason is only accepted by ship kit makers, paint shops and apparel stores. A stretch, but not impossible.