I think some of you may have misunderstood my post, so I will try to explain it better.
People have different opinions,ethics and morals, different interests and hobbies, different likes and dislikes.
Many people simply have no interest in animals. They don't think twice about animal issues such as welfare or rights or rescue. They eat whatever meat is put in front of them, don't keep pets.. etc. It isn't that these people are cruel or anything - they are just not interested in animals.
Many people are interested in and like animals - but this varies to different degrees. At one end of the scale are the people who are pro-rights, vegan etc who do everything in their power to help animals. But such extreme examples are very few and far between in the grand scheme of things. Most people are somewhere in the middle. A great many like animals enough to want to keep pets, but that is all. They have no interest in animal welfare issues. For example, most of the people I know fall into this category. They know about all the animals in rescue and being euthanised for want of a home - but they will only buy from breeders for whatever reason.
Look at the people who shop in pet stores - what do they have in common? They like and/or are interested in animals. They either keep pets or are intending to get some. You have already eliminated all the "not interested" people in society. Because these people already care about animals, there is a high chance you could educate them animal rescue etc and cause them to change their own behaviour. (Even in this animal-liking group you won't change everyone).
The same goes for forums like this. When we try to educate new members we have a high chance of success, simply because if they didn't care about animals they wouldn't be on an animal forum in the first place.
In these two scenarios we are preaching to the "already half-converted". They already care, they just need to know how to act upon it.
Now consider all the people looking for jobs. This will be a cross section of society and include all the groups I have mentioned, from the cruel and uncaring, to the people with no real interest or concern for animals, to the animal lovers, to the animal rights activists. The animal rights guys wouldn't work at a pet store. The animal lovers proabably would quite happily unless they can be educated and convinced not to. The people with no interest are not going to be convinced.
If the pet store was interviewing a potential employee I would like to think they would choose the animal lover over someone who doesn't care. But, take away the animal lover and the store will simply employ all their staff from the "don't care" group.
I honestly do not think that there are enough people in society that are educated enough and care enough to refuse to work in pet stores. Stopping animal lovers working for pet stores is never going to result in them closing because there all always other people to fill the gaps.
On the other hand, the customers are already half way there. They already care about animals, so convincing enough of them to stop buying animals is definately possible. You don't even need to convince ALL of them - just enough to make selling animals no longer viable, so as to pursuade the store not to bother selling them.
Having animal lovers working in pet stores can only be a good thing. Partly because they can improve the lives of the animals in their care. They can also educate. These people can - on the sly perhaps - recommend that people adopt from shelters. They can give links to this site (which in turn is pro-rescue). Surely its better to have an employee that will suggest rescues than one who will pressure people into buying?
I am not being defeatist.... I honestly believe that we SHOULD try to stop pet stores selling animals, and that we CAN succeed. But this is best done through the customers - not the workers. Surely, we should be trying to get more educated animal lovers into these stores where they could make a difference? Consider this - if one of us worked our way up to the top of petco or petsmart we could change company policy immediately to stop selling animals. I just think that taking the animal lovers out of the company will only make it harder to change these companies for the better.