If you are in the scene long enough, you should have known that there are some uncooperative clients that always send 0% (Xunlei being one of the more notorious example with their VIP schemes, and later on they would straight up spoof their client string when people started blocking them). Being a leecher nowadays is almost a norm for a lot of users, and I don't blame them since they are afraid of consequences in a more regulated jurisdiction. But a must seed when leech requirement? Hoho no, that's more like a suggestion.