Place holder sets

[Revenant]

If you look at pretty much any set category you'll find several sets at the bottom of the ranks with no coins in them. If these sets were made in expectation of a coin that hasn't come yet I could understand. If I've just won a new coin I'll sometimes open up a new set and leave it empty for a day or two while the coin is being shipped. Some of these empty sets have been left sitting for over a year though.

 

These sets, which I refer to as "place holder" sets don't do anything and contribute nothing to the registry. So, my question becomes, why not delete these sets? For that matter, couldn't something be set up to automatically delete a set that has gone coin-less for more than a month (or some other arbitrary timeframe).

 

I bring this up because it's just so strange to see the sheer number of empty sets there are. They're even assigned a rank in the registry, even if it is the lowest rank.