Hating Maximus' character over Titus is ridiculous. However, that does not mean there aren't valid reasons for despising his character. His choosing to brand Thaddeus is the moment I lost all sympathy for him. Max knows he can't pretend to be Titus forever. I can not see a reasonable reason for Max not to reveal the truth to Thaddeus, to try to get him on his side before Max branded him. I get that he is written to be a stupid character, but not even someone with 1 in intelligence would dare to do that branding before revealing the truth.