But they dont refuse your cash because they dont like the person who had it BEFORE you.  They have no idea who had it in the past, because cash is fungible. 

In other cryptos they can threaten to blacklist your coins based on any transaction in its history being put on some blacklist, provided they can sufficiently threaten/control miners to do so.  In Monero they cannot, because it is actually fungible like cash (moreso even, since cash has numbers identifying the bills, even if they arent really used).