That is too bad about the one cast member trading off so many to the same person. However, I don't think there is anything bad about the CMs having to accept scrapper pins. It would take the fun out of trading if they were allowed to say no to any pins. Also, most people don't know and/or don't care. As they are simply doing it for "trading", I like the must trade rule.
As to scrappers . . . a friend did a fun experiment. She got a Tsum Tsum pin and someone told her it was a fake because of colour and the back edge and something else. So, she went to MK and bought 5 more of the same pin and they each were totally different. Multiple shades of colour. Some smooth edges, some not. Some wavy enamel, some smooth. It was very interesting. I got an Obi Wan pin from the park and a known scrapper version, and you know . . . the scrapper had better enamel and smoother edges than the Park bought one.
Then, on the other side, I traded for a couple of these cute square cartoon face Pooh pins, and one was really nice feeling and the other weighted less than a penny and was super rough. You could tell just picking it up for the first time!
So, some I can tell, others I can't. When it comes to trading when we get to go to Disney Springs, Sis and I don't really care, as it is for the fun of trading that we do this. We simply collect for the design we like for some reason. When we go to Disney Springs once a year, we take every pin we have that's not a "must keeps" on the boards and trade them. It is so fun to trade! I don't even care if I trade for something that isn't on my want list, as I just trade with anybody! -grin- So, we rotate our pin collection that way.
Not the definite keepers, but everything else!
Also, you have to know --- Disney allows scrapper pins to be made, to be sold, and to be traded. I've seen them jump on things much bigger than scrapper pin dealers, and if Disney was not allowing/behind the scrapper/cheap pins - they would be off the market in so short a time it would take you breath away. So, Disney is not going to be bothered until they decide to not allow it. They are totally allowing them. As it is a "trading" hobby, I'm sure it doesn't matter to them if their CMs are wearing all legit pin or all scrappers. Collectible pins are the ones sold at more prices and sold as collectible pins. Trading pins are something else. When it comes to pin trading . . . the trade is the thing, not the pin value.