<<Having sat there for 20 secs or so, we're hardly likely to wait another minute or so ......>>
You may not, sir... but others...........
Remember the old story from Chicago - blinding snow and a certain British aeroplane received a similar instruction. As the lander turned off the runway - seen by ATC and not the British chap - ATC said "*** cleared immediate take-off". Mr Bulldog said: "We'd prefer to wait just a minute or so until we can see the runway is clear". ATC replied: "*** just shift your ass"... whereupon he did just that!!