You said it. Tailwind. For this approach, 9 times out of 10 the decel+descent is also the turn to base leg which also usually has a tailwind. If you don't speedbrake it, you catch the fella in front fairly quickly. The decel with F1 (slats only) is not sufficient to meet ATC's requirement - they do expect us to do as asked promptly not in our own time. Of course if you can see you're going to get a extra couple of miles or there's no critical preceding traffic then you can give it your best shot "sans speedbrakes" - there's always the gear
I'm still nailing my colours to the speedbrake mast!