I have noticed this concern as well. The rate gil is leaving the economy at level 50 (via AH tax, teleporting, repair bills, etc) appears a lot higher than the rate new gil is being created from sources external sources (leves, dungeons, fates etc).

Crafting only reshuffles the money the gil already in the server global economy. Yes, you gain money doing it, but someone else is losing that much so its still the same value to the servers total economy. For the system to truly work, people need to be able to bring in new gil from the world to balance out what the game is taking.

Currently this is being hidden by all the new players hit 50 each day with all their level money that's adding into the servers economy. Once a majority of players hit 50 though and that resource drys up, its going to become a real issue.