It is precisely FUD. If you don't have actual hard facts and can specifically identify and explain an actual mechanism of failure, you are relying on Fear Uncertainty and Doubt. "yes, I could be wrong" = FUD.

Also your claim about "most anon technologies" and "most respected and talented developers" falls apart when looked at carefully. Your evidence is that you cherry picked some projects and personalities that support your premise. Even then the people you cite don't even agree, at least not unconditionally. For example, are you aware that jl777 is actively supporting BBR = on chain anonymity?