Because some of us have 9+ accounts that we bot on and you get to a point where you kind of get burnt out shuffling everyday just to make a bit more profit. I can hit one button to sell all my gems for 5g each and same me alot of time and get back to farming. You have to put time into your equation when you are discussing profit. If i tried to squeeze every bit of copper out of my botted materials i would die from insanity.
Pretty much this.
I run three bots, I don't have time to process all this gear and I don't have the market to buy 1000 plus rings that I make. Time to profit ratio, I'm better of vendoring and sticking to cutting the infernos and selling those when patches hit. I guess you have to do what works for you, depends on how much ore you are moving and your individual situation.