It was Maximus's own fault...

You fail to realize Roman virtues of the time.

The Romans respected/admired courage, blunt truthfulness/honesty and openess. And despised deceit, tricks and underhandedness.

Why you think Aurelius decides Commodus is not a fit emperor? Because he lacked the qualities the Romans admired, and had all the ones they disapproved of.

Thus, Maximus would NEVER resort to deceit and treachery even if it would mean an easier victory, regardless of whether they were justified or not.

In other words, Commodus would have been a GREAT Mycenaean Greek king, where all those traits were indeed admired (rememeber Odysseus). He just was born a millenium too late and in the wrong place.

Not necessarily. Rome was never a democracy in the modern sense of the word, even before Julius Caesar. When Marcus Aurelius stated that Rome was to be a republic again, this did not necessarily mean a democracy. Maximus's legions could have easily dealt with any popular revolt quickly. He could have justified the coup by painting Commodus as a degenerate who would have bankrupted Rome.

The point I was making was that Maximus acted rashly by snubbing Commodus's offer. A little hypocrisy on his part could have saved his family's, and ultimately his own life too.

True, but don't you think he would have faced a massive revolt from the Roman people if he killed their Emporer? He spent half the movie trying to win over "the mob that is Rome" for a reason.