I think the guy's a complete loser in the series. In a way, he's similar to the Earth Queen, Ozai, Long Feng and several others that hate the Avatar. He's just a guy that wants to be in control and be admired by the people, but has no interest in adaptation or acceptance when there is trouble brewing.
He's a conservative leader, no doubt he does look out for his people, but his methods are confined. Meaning he didn't want to get involved in a war Republic City had nothing to do with such as in Book 2. In Book 3 he just as the entire city is fustrated with the daunting vines that plague the city, I mean those vines aren't just an inconviniences, they are causes large amounts of people to evacuate many parts of the city that are being overrun and destroyed by the vines, most likely causing skyrocketing homelessness, shut down public water supply which is a huge problem. While his actions themselves may not be the greatest, they are all made within some sort of logical reasoning.
The Earth Queen didn't give a single hog-monkey about her people, she was a complete selfish tyrant.
Ozai and Long Feng were power hungry, Ozai wanting world domination, Long Feng for complete control of Ba Sing Se.
Raiko is just trying to keep his city in tact. It's hard to accept change when that change is what's destroying your city and is the core reason everything is falling apart.
Still, he could use a lesson in acceptance and admitting that he was also at fault for what befell Republic City, since he chose not to get involved in the troubles of the Four Nations. The United Republic of Nations is an extension of the Four Nations, which makes him an extension of the people that helped to build it decades ago. Instead of helping the good guys stop the bad guys, he took the road of cowardice. I wouldn't have a high opinion of him myself if I lived in Republic. I support the Avatar.