From a recent post on another thread Shaggadelic actually mirrors my opinion of the matter:
The way I see it is, if a player has found a means to take advantage of the way the game works, then you are within your rights to do so... Ideally, if it is something that is a bug or something that would lead to a serious game imbalance, you should report it as such - and then you can continue to take advantage until the programmers fix it. That is the honest thing to do...
That being said, AFK farming is currently a viable way to make money, but it won't be after the update so enjoy it while you can. Personally I don't do it, but that is just because I don't like leaving my phone on all night, and I much prefer earning my keep the old fashioned way.. It is a feeling of accomplishment! (And I have earned lots of gold, you just gotta kill smart, and look for four stars )