Indeed!
Looting a mob takes less than half a second without travel time and about a second with average travel time included. The average value is probably some 50s, so the income from the action of looting already dead mobs ends up close to 2000g/h, and even more if it doesn't delay the pull (the time spent looting worth of your DPS as damage dealer and no opportunity cost at all if healer). The only excuse of not looting the mobs is to be a tank (the role that ends up dictating the pace) who reliably gets over 2000g/h from other sources, or having so much gold already that you'll never need to put any effort to getting more of it. My approximation of profit might be slightly wrong, feel free to give more accurate numbers.
I really wish that Greedygoblin-esque (or simply "rational") way of thinking about WoW-economy became as widespread as many other philosophies before it have in the community (such as "you have to read Elitistjerks to maximise your potential"). Goldsellers and "how to make gold" threads would almost completely die out, and player wealth and profit from different actions would level out so much.