There is an unlimited supply of gold though. Wartable missions
Gold is limited not just by quantity but by availability.
The most gold you can get from a single war table mission is ~250 (and it requires Leliana and a very lucky roll), and it can take 45 minutes or more. It will require substantial investment to acquire enough gold to readily purchase the rarest equipment (which is the point of the currency system in the game—you have to earn the gold if you really want to buy expensive stuff).
You can also farm unlimited crafting materials, but this too requires significant investment.
That's why the rarest equipment (and thus the gold used to purchase it) has value: it's really hard to get. If you just make it freely available, it devalues not only those items but also everything else in the game that was given without requiring gold.
As I noted before, I wouldn't be opposed to BioWare adding cheat codes that let you give yourself gold or even just spawn the items you wanted. But fixing that merchant was necessary for all the players who don't want to cheat (and for BioWare, who has a clear idea in mind of what they want the gameplay experience to be).