I agree that its a bad idea, it makes no logical sense for a start, how can someone carry around -infinite- arrows, if thats the case i want my lancer to do infinite damage and fly on my command >.> It is an awful idea, the sale of arrows would really stimulate the economy, not to mention people selling the items to MAKE the arrows on the wars more (coral, obsidian, etc.) people sell it now but it is by no means something to farm. The sale of arrows would make a large difference to the use of gil, that is, if SE made arrows actually do something. The amount of ARC in the game atm, if they made the later rank arrows powerful i doubt they all have a high rank CRP to make them themselves :P

In summary, id say in a lesser mmo, infinite arrows would be easily understandable, but in a well established MMO with features such as gear damage that make the game a more realistic experience, 'infinite arrows' just doesnt make sense.