It's not really about respect for the characters so much as it's just...one being significantly more wrong than the other. If people wanna ship DamiJon (provided it's nothing sexual) that's still weird and I hate the idea that two people can't be friends without instantly being paired together. But it's not really crossing any serious lines. The same can't be said for any scenario involving Dick and Damian. That's just wrong from every conceivable angle.