Yes you can sortof get "banned".
More exactly, you can lose the right to use the Money Back Guarantee. Not only does processing claims cost eBay money, but buyers who are making "too many" would appear to be either unable to learn how to spot a bad seller or an active scammer making fake claims.
This is also why many sellers will not entertain bids or Best Offers from customers with a lot of negative feedback left for others nor from buyers with Private Feedback.