True, but that balance is going to be different for every application domains. At the end of the day, one of the few metrics which really matters is the return

True, but that balance is going to be different for every application domains. At the end of the day, one of the few metrics which really matters is the return on investment. A lot of software can afford iterative improvements as well, so its a great idea to start off with extreme convenience and optimize as you scale.