Button was "smooth" because he did the classic geometric cornering line with single application and then removal of lock as the corner progressed, applied the throttle progressively etc. Lovely and smooth. And sadly not the fastest way to drive some of the cars of recent years. Also, it hampered him when the car was less than ideally balanced as he would have to wait for the car. Hamilton would be quick almost all of the time by being able to adapt his technique to the car. Button said as much in interviews about his time at McLaren with Hamilton - he is only properly quick when the car is where he wants it, but Hamilton was always quick - and that is a flaw, to be honest.
Look back at Senna's approach - he had a bizarre technique with the throttle where he would pump it up and down in a corner. Not "smooth" but certainly one of the quickest drivers of his day, if not ever.
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"