I know this is a joke, but pretending for a moment that it isn’t: this would immediately result in the rep system being gamed the same way it is on eBay: scam sellers can purchase feedback on cheap or self-shipping auctions and then pivot into defrauding people on high-dollar sales before being banned, rinse, and repeat.
>>zbentl+(OP)
Let's also see the differences: On github you can always see the interactions. On ebay, once a sale has been made, you have no idea what happens next. On Github you always have all the artifacts of where the reputation comes from.