To proponents of the banks having infinite money; that just leads to inflation. FO2238, like other MMOs, already has a source of infinite income for player to exploit: infinite encounter NPC. And just like other MMOs, inflation is the perpetual threat to in-game economies. Everyone wants to be "the hero" player with all the loot/money, and as a result the player-base accrues such vast wealth grinding npcs and quests that the in-game economy becomes a joke. Think about playing F2 just as a single player game. Once you got to around VC you could pretty much make infinite money just by selling random encounter loot to npcs. In 10 minutes you could gather enough H&K CAWS and cash in at VC vendors to buy a GECK (the map to V13 was only 10,000 creds). Now multiply that by a few thousand players and there's little wonder why people start begging for wipes a few months into the game.
wipes are so far the only way proven affective to bring the economy back to something manageable. When money's value per person becomes too diluted, there are very few ways of equitably readjusting its value. There's a reason we aren't still using dollars after the great wipe war, the number of bills and coins (required for a population of hundreds of millions) becomes worthless as a limited commodity when the population drops to mere thousands. Caps on the other hand, were relatively uncommon, since they tend to be discarded, and limited once the ability to manufacture them was nuked away. Perhaps every few months we could change currency (oh I'm sorry, we don't accept "caps" anymore. Haven't you switched to "Hub-bucks" yet? I suppose I could exchange them for you 100:1, but only cuz I'm such a nice guy.)
The fact is, even without banks, and infinite money, people can still gather enough resources to literally carpet their tents with Combat Armor. If anything, we need resource sinks like the banks (or better yet, more resource intensive, xp/perk-payout only quests) to keep credits from losing their value. I would even advocate that banks go without interest AND charge a regular service fee (though in return you ought to be able to access your one account from any FLC, maybe also have the option to rent a safety deposit box...) After all, this is the wasteland; you could be robbed or worse at any moment. Having your money guaranteed safe is something many people today in conflict countries actively pay for.
That said, I'm curious where new account fees go, as well as the assets of banned players. I'm also curious as to whether game-wide caps level has an effect on merchant buy prices. Or if there is any resource transfer between merchants and their town's bankers during restock.
tl;dr: allowing the banks to "print money" to match non-constructive interest debts only dilutes it's worth and accelerates the need for wipes.