Absolutely not. When I create projects I only credit other existing systems if they are a direct inspiration. If I independently come up with the same idea as someone else I see no reason for me to do the due diligence and credit them.
Okay, well, in this case (even accepting your argument) I've been told there is direct overlap in contributors so there is no feasible way they couldn't have known.
Okay, well, in this case (even accepting your argument) I've been told there is direct overlap in contributors so there is no feasible way they couldn't have known.