People with a hidden private feedback rating of 100% make it look like they are perfect on the surface in almost every way. Given you can't read their feedback comments, it is another reason to convince eBay the honesty of providing a more true indicator of a member's transactions. A negative rating must be given when a strike is applied, only then will we have an instant view of a member's true overall conduct.

EVERY buyer on ebay whether they have (private) or (123) feedback has 100% positive

if you   click on the word (private), you will see the number of transactions they have received positive fb for in the last 12months ... a good indicator as to how often they use ebay.

as fb is voluntary and many buyers and many sellers never leave it, it is always just an approximate indication of the transactions conducted on ebay.

the majority of good Sellers have their blocks in place to stop buyers with more than 1 non payer strike from ever bidding on their items, check of your block bidder activity log will show how many serial non payers have attempted to buy from you, if you have such blocks in place.