We need to be careful to lump-categorize importers as "unethical" as this is far from a black-and-white issue. Not everyone will agree to do this and not everyone should be expected to so (especially those whose motivation is their livelihood and not just at the hobby level).
We have no authority to force people to follow or not follow the Compact - it would be a voluntary agreement, not any nation's law. As far as ethics are concerned, each person aware of the Compact would have to judge for himself whether the idea and its execution are "ethical."
A lot of exporters and importers WON'T agree to this, at least not at first. But some will. And more will if they see that it matters to their customers, out of commercial necessity. We could No-Trade list 50 species in each lake, and they'd still have PLENTY of fish to export or import. And the upside to this method would be that the listed fish are NOT listed permanently - they are just being given a break from collection for a few years until the wild population recovers. The whole purpose of this is to be sure that wild fish remain available both in the lake, and for export, indefinitely. We are talking about WISE use here, not NO use.
Should a club join this Compact, could they earnestly display the seal if not all the club's members have signed-on? I am not trying to get the cart in front of the horse or poke holes, just trying to get thought out there for discussion.
As I see it, a club that joins the Compact would be agreeing that No-Trade Listed fish will not be sold through the club, either at auction, at meetings, or through ads on forums or in publications. It is beyond the authority and resources of a club to police it's members fish rooms, or their activities away from club meetings. But a club can and should control transactions at its own meetings and through its own online and traditional publications.
And remember that all that's being restricted here is the SALE or PURCHASE of WC fish on the No-Trade list. It doesn't mean I can't OWN them, and it doesn't mean I can't GIVE THEM AWAY. If I had a breeding colony of, say, wild-caught Ps. Saulosi, and they appeared on the list, I would not be allowed to SELL them as long as they are listed. I can and should, however, breed them and distribute as many F1s as I possibly can. Sale and distribution of quality tank-raised fish decreases the demand for WC fish, and thus helps to protect them.
Now, as long as my WC Ps. saulosi are No Trade listed, I can't SELL them, even if I bought them before they were listed. I could, however, GIVE them to someone else for free. The purpose of the Compact is to make at-risk WC fish commercially valueless, while enhancing the value of quality tank-raised fish. We're not asking people to get rid of the WC fish they already have, and we are certainly not suggesting they should be destroyed. We are simply establishing that they are TOO valuable to the entire world to be traded by individuals for a profit. No-Trade-Listed fish need to be treasured, protected, and propagated, until there is no longer a need for them to be collected.
Once the wild population has recovered, it may be possible to de-list them, and import new wild stock, at least for a while. Actually, that would be the ultimate victory and vindication for the Compact - fish that were collected to near extinction, then were given time under the Compact to recover to the point that they could be collected again, at least in limited numbers.
If we DON'T do something like this, we are quite likely to see laws enacted similar to those that apply to the national park in Malawi - permanent, imprecise bans on exportation of all the fish of a certain species, type, or location. What happens to us if the current threat to That Yellow Tropheus led one or more governments on the shore of the lake to ban collection and export of ALL Tropheus?
It's actually very much in our interest to regulate ourselves, before governments step in to do it for us. That is why we have an MPAA, btw. There was a growing movement afoot in the middle of the last century to create a government authority to control motion picture content. In order to head off what amounted to censorship, the motion picture industry got together and created the Motion Picture Association of America. The MPAA exists for one reason: to provide a set of standards by which movie producers (or their delegate, the MPAA) can rate movie content, so that the government doesn't feel the need to step in and do so for them. What we're talking about here is something very much like that - an association through which the aquarium hobby and trade voluntarily polices itself, before governments come in and start doing it for us, in ways we won't like.