So just because something is hard to detect, it should be legal? That sounds like a poor argument to me.
In addition, there are extensive statistics to monitor, and its not as hard as you think to detect. If you disagree, I am sure you can try it and find out. But even beyond that, it is in the sole discretion of the admins to decide who is farming or not. Its not like they have to prove it first with a photo of yo doing it, and then if they don't have one you can laugh and say "ha ha can't prove it so you can't punish me!" No, they will enforce anyway, if they believe it.
This is a pointless thread, please, everyone respect the rules whether you like them or not, or risk facing the consequences.