Not only that, but when some terminal program decides to spew a bunch of output again and you don't want to interrupt it, you're going to have to wait until it'

Not only that, but when some terminal program decides to spew a bunch of output again and you don't want to interrupt it, you're going to have to wait until it's finished before you regain control. No one wants to waste their time waiting for something that could be done already. So faster terminal output can make a real, useful difference in everyday use.