I had a soft spot for him in the same way that people have a soft spot for their crazy uncle who is a bit racist, sexist and homophobic, but is usually good for a few laughs and generally harmless because you only have to see him at Christmas time. You know the type, every family usually has one.
But every once in a while, that crazy uncle goes way too far and says something that can't be forgiven or laughed off as, "just crazy old Uncle Bob". Usually that is something like endorsing Hitler or the Nazis. Then crazy old uncle Bob gets told to leave the house.
That's my view of Bob Katter. Usually, his brand of politics is just so silly that he is laughable and essentially harmless. Endorsing a Nazi is not laughable and harmless.