Hastily accusing someone isn´t a good thing to do.
(isn´t a good thing to do -meaning - you shouldn´t do...): you shouldn´t accuse someone hastily (without evidence).
You could also use "it´s shameful/outrageous" in the sentence if you want it a stronger disapproval of the attitude.
It worth pointing out that "acusar" could also be "blame":
Being too hasty in blaming others is not a good thing (to do).
And I am sure there are other ways to express that, let´s wait for more answers and see.