I'm an eBay seller, but if rather not reveal myself if I have to, thanks. I think bitcoin will be great on eBay, but to be honest, it won't change a thing. Not enough people use bitcoin for eBay to care. What I do, is convert my sales into bitcoin. Pretty much no difference.
I would rather people pay in Bitcoin because then paypal cannot allow them to chargeback.
I agree with what you are saying, but like these scam EARN BTC sites, there are scammers on eBay and those sellers are just going to rip you off. If you are a buyer, you want to feel protected when you are going to make a purchase in case there is a bad seller, you can get your money back.