The problem is they hide this problem away and in no way warn you, I fully accept that they might not want to prioritise fixing this, I just ask for common courtesy - I had a month with dropbox basically not working at all. Popping up a warning isn't bending over backwards.
I wonder what would happen if this occurred on gmail - you have too many emails so suddenly it stops working without warning, completely, irrecoverably. Would you still make the 99.92% vs. 0.08% argument? Or would you find it a bit off? At least warn + give a way out...