Well, to say I am dissapointed in this decision is an understatement.   He has the look, of that there is no doubt.  But Drax isnt some silent  muscle man, he speaks, he is a master tactician, hell he taught Richard  Rider to fight in Annihilation.
His whole family was killed including him and then he was resurrected  for the sole purpose of killing Thanos and getting revenge.  He also has  to find out one day that his daughter survived.  When he says things  they meaningful, powerful and to the point and in dire situations he is  the man you want making decisions.
Sorry, but from what I have seen of Bautista he just cant convey this  with his acting ability.  His casting makes me worry a lot about the  characterisation of Drax as well, if he is not going to be what I  described above, then he isnt going to be Drax I am afraid.  My  anticipation for this movie has gone down quite a bit, as Drax is my  favourite character from the team and the one I know most about.
My only hope is that his screen test was amazing, and Marvel were so  impressed they signed him up.  I have never hoped to be proven wrong so  much in my life, so come on Bautista, prove me wrong and give me an  awesome and faithful Drax.