We can use the example numbers provided here(5500 DPS, 8 min fight) to put this into context. Lowering your DPS by 10% because you couldnt be bothered to press 1 extra button would reduce your contribution to the example fight by more then a quarter million damage. If you stood still and did nothing for the first 45 seconds of the fight and then contributed at the full 5500 level you would be doing roughly 17k more damage over the course of 8 mins then by skipping that one buff. Or to put it another way, a full party who all felt the same way about skipping out on a 10% bonus would increase the length of the fight by 90-120 seconds. Thats a LOT of time for something to go wrong or to hit an enrage timer and cause everyone to fail.

And someone correct me if im wrong, but isnt the 'goon rotation fairly well timed? Dont you end up refreshing HT every 2 or 3 combos with no real hassle? Or is my understanding out of date?