I don't totally buy into this 'Drones only have one function' mantra - as nature is not normally so profligate. But even if this is the case - it doesn't follow that drones sit around the hive all day on their butts doing nowt.
Go find yourself a virgin queen - and take her to the most isolated spot you can find, and let her fly. Chances are that she'll come back mated by a good dozen or so drones. So where did those drones come from ? For sure they didn't get an email advising them: "a virgin will be flying today at 1500 Zulu at the following GPS coordinates ..." !
Each day, providing the weather is reasonable, each hive will put up a fair number of drones which will be flying around 'fishing' - with many just circling around their favourite fishing hole on the off-chance that a virgin might come flying by, with others fancying their chances much further afield. Now 'pre-loading' strategies of that type are very expensive to run in terms of participant numbers: with the vast majority flying around all day with absolutely nothing to show for their efforts.
And so they return home after another fruitless day at their airborne offices for a bite to eat and a few hours in the armchair, before taking off again the following morning on yet another prospective sortie. And the next day, and the day after that ...
Life isn't necessarily one of lazyiness for the drones - it just appears to be that way to those who see it thus.
LJ