I've needed this loads of times. Not a lot, but yeah. Especially due to the fact that I usually buy high end boards and they usually have lots of cooling above the slot, meaning once the GPU goes in you can't access the release mech.
That said unless it's a serious fiddler rig like my Alienware on water then I really don't see me using it that much. Especially now that GPUs are like rocking horse poo, so the chance of changing one out is becoming increasingly thin.
And at this new trend in pricing? that just gets thinner. Especially because so far "next gen" games have done absolutely nothing to worry me whatsoever.
With Pascal, IMO, Nvidia released too much power. If you have a high end Pascal or Turing card there is absolutely no point in buying any of the 30 series.