I think it's A-OK, as long as it's for gil and not for real money.

An MMO has no defined objective. It's up to the individual player to decide what they want their endgame - their "story" - to be. If someone wants to be the capitalist baron who hires other people to do the heavy lifting for them, and they have the skill and time to acquire enough gil to do so, that's fine with me. There's nothing about Titan that makes that fight more "sacred" than the crafting system or anything else in the game.

The only point where it becomes a problem is if they bring in resources that other players don't have access to (or have agreed in the ToS not to use) - such as bots, hacks, or paying RMT - to accomplish their objectives. At that point, it's cheating.