Before the requiem flute, the Shofar +1 had the highest +requiem on it, making it better than the siren flute and hamelin flute in regards to requiem. Thus, that is not the only reason this horn exists.
I don't think Requiem is garbage. Especially with all I've heard about it basically winning the Maat fight for you. Only way I see this benifiting is if you got the Shofar +1 though (+3 to requiem <Hmmm.> <Yes Please>