I have noticed that as well. Most of the thread I have read almost everyone takes a massive interest in them and then in turn tell the person how wrong it was to do, they should cull them, etc. I can almost guarantee there is a few people on a certain frog board that can name every member that has posted with a mixed tank and or hybrids, and if those people start to sell frogs then they will be questioned watched more closely. Again not that that is a bad thing.
I know from chatting with people off the frog boards that they will not buy nor sell to any one who has produced hybrids, has a mixed tank or even hinted at a mix tank. Now that is not every one but some of the larger breeders that I have talked to and become friends with over the years.
The mixing threads are always heated on frog sites. Some people really take it seriously ( which is not a bad thing) and some people ( most less experienced from what I have seen) blow it off like no big deal. People debate mixing almost as much as the debate the legality of some frogs.
I do think the zoos are able to do it due to the larger enclosures, experience levels, and alot of them keep frogs of the same sex so there is less chance of fighting, stress, bullying and no chance of breeding.
NO these frog we produce will never be introduced back into the wild but it is still important to the dedicated people in the hobby to keep the lines as pure as possible. This is a hard thing to do, especially with people mixing frogs, selling mislabeled frogs and generally not giving a crap about the hobby.
Ok done rambling now.