After thinking about it, I don't know why this is being hated by any one.
Is it because he is young? Skinny? It cant be because he is a bad actor or because he has been in bad movies, because that is not the case. If this was later into his career I think this would be met with a different response. I honestly think he might just kill it. IMO WB has never made a BAD casting with its villains in recent years besides the Hector casting in Green Lantern movie but even then Mark Strong as Sinestro was almost spot on.
I love Affleck as Batman, sceptical of Gadot (though ill wait and see), and love this.
Very interesting casting IMO