I think the biggest mistake that the so called "Straight Arrow Jedi" made was denying their emotions. By doing so they just became no better then droids to the Republic and Jedi Council. Which in turn made them easy to influence and also easy to kill. They trusted the clones too much and when the clones turned on them they had no hope of survival. Also they trust in a prophecy and a dead Jedis word then the signs in front of them.

This is just my mere opinion take or leave it as you will.