They do it out of indifference. If they had their legal team spend time on figuring out how they can allow these coins within the letter of the law they would spend 10,000 times as much money on manpower as they would ever make on seller fees from these. So they just ban them. Of course that's what they would do.
It seems like it would be so easy to regulate this with items that have a date stamped on them.... I would personally have no regrets buying coins minted in DPRK, Iran, Cuba, Syria, etc., as long as they weren't coming directly from that country. Wait, what? When did this start? I want to see all the listings.... :/
Sadly it has been that way for a long time, just not everyone realises it. In the UK we have to pay extra to get our listings visible in the US and Canada - and even then it does not always happen. It is fairly random whether we see listings from the US. A tip: your userid with Ebay works in all the different countries, so if you are seriously searching for particular coins it is worth logging on to different Ebay divisions to do your searching. For example, many US and Canadian coins sell for a tenth of the price on Ebay.co.uk than they do on Ebay.com.
It seems like you are a paying store owner there who gets more free listings. I am not and I only get the standard 50 free listings per month and then whatever random promos they decide to give out. The problem is when they give a promo for 100 or 200 free listings and I use it, but when a month goes by, those are all scheduled to renew automatically, and this time I'm going to get charged a fee for every one of them if I don't cancel it. So if I'm not paying attention I can end up incurring $30-$60 in fees. If the automatic renewals were free I'd be all for it, but they aren't.
I agree, which is why I think it has been such a mistake that eBay seems to want to be the next Amazon or go head to head with them. Which just shows how poorly managed they are. How many college degrees does it take to realize that different categories should have different policies. It's really not rocket science that dvds and coins shouldn't have the same policies. They also seem to forget that many of their buyers also at least occasionally sell on there and when they get jammed up by a bad policy a number of them will stop using the site entirely. It was buried in a seller update quite a while ago that they reserve the right to hide listings to give others a chance to sell blah blah nonsense about being fair to other sellers or something crazy like that. It really got noticeable when they switched to their new search engine in the last year or two. It's one thing to do that with blue rays or whatever but collectables should have been excluded not treated like they're all identical.
Although they certainly have us "in mind" enough to prohibit use of gift cards and many promotional discounts in our categories.
It's very likely playing a role is not a significant one. A lot of people seem to notice Their sales fall off a cliff when they reach a certain amount each month then when that falls they magically come back again. Also there seems to be more than coincidental geographical groupings during order spurts
It's a wonder they didn't ban all coins from the Spanish Empire just to be sure, along with any coin struck at the San Francisco mint since it too was once Spanish territory.