Why? Because vendors often have a change of heart when they see they won't be making any money or losing money for the huge risks they take. I've seen it many times before. Bitcoin tanks and everyone thinks FE should be fine because they FE'd last time for the vendor and everything went smooth. But this was the time vendor decided to take the money and run. Exit scamming. Selective scamming. Canceling orders. The old bait and switch. Excuses galore. You name it and the chances of it happening when bitcoin tanks goes up. Buyers just be careful about where you decide to spend your hard earned bitcoins and be extra careful not to get ripped off.
The only positive thing about it is that it gives vendors more incentive to get the packages out quickly and in our hands as quickly possible. I know personally as soon as i get it, i finalize the transaction and i would hope the majority of people to do. I know my last order took 12 days to arrive in domestic regular lettermail. Well the vendor would of lost less money if they paid for express shipping out of their own pocket, cause i would of finalized within 1-3 days instead of 13.