Why would you blame them for their works? They didn't do any wrong by writing their histories. I might criticize certain aspects OF their works, like the exaggerations and fantastical inaccuracies, but even these are not direct faults of the authors', rather the sources available to them; and they often give the reader fair warning to these likely fallacies. Overall Herodotus and Thucydides should be commended for their works since they are so indispensable to understanding the history of Classical Greece.
Here is the first line of Herodotus' work which I can only see as a great service to mankind and the preservation of his past:
"These are the researches of Herodotus of Halicarnassus, which he publishes, in the hope of thereby preserving from decay the remembrance of what men have done, and of preventing the great and wonderful actions of the Greeks and the Barbarians from losing their due meed of glory"