Then you should read the convo.
Easy, for now, Luffy has hatred for Akainu, not Blackbeard, claiming otherwise is contrary to the manga.
His relation to BB will change obviously but that´s the status quo.
Luffy blames Akainu for Ace´s death, he used to have nightmares of the fisting, the one time he heard the name Akainu he showed anger and pain.
When talking about Blackbeard, with Blackbeard and so forth, it is never about blaming BB, nor hatred.
He dislikes him right now, but neither in FI, Dressrosa, or on the way to WCI, he showed a specific rivalry.