We're not talking about a $200 chinese wheelset with some fake Zipp logos being sold for $1500. Authentic Shimano cleats retail for around $20, so the wholesale cost is probably about $10. Why would someone bother making fake versions?
It seems like the cost of buying generic cleats from a wholesaler, then developing fake labels and packaging, and listing on Amazon + storing and shipping wouldn't be worth it for such a low-cost item with already razor thin margins.