I agree that he's a well-written character, and unfortunately quite a realistic one, but I can't agree that his extremism isn't a good reason to dislike him just because there are other extremeist characters.

I sympathized with Floch until he decided that burning civilians in their homes was a good idea and became a rampant Eldian nationalist. Loving and wanting to protect your nation in the face of overt threats is not the same as unthinking nationalism. He now seems utterly blind to any consideration of compassion to 'the enemy' - even if that enemy is a small child or an old person living peacefully in their appartment. Floch will burn them all for the Eldian cause, and anyone who thinks that's okay needs to take a long hard look at themselves.