Well, for them to consider Tatsuya to be defect even though:
- He's better at using magic than them, considering he easily develop new awesome magic for others.
- He's so good at CAD development that his dad has to use his intellect.
- He's obviously the most powerful magician in Japan. Totally different class than the rest of them.
- He's smart that he almost got all perfect scores for his entrance exam. We don't know about how much Miyuki and Mikihiko got but I guess Tatsuya might beat them by a large margin.
- His magic are so unique that only he himself in the whole world possess them. Materiel Burst, demon's right, divine left, regeneration surpass that of Wolverine's, eyes that can see and analyze any magic etc.
- He's probably the 3rd or 4th best at ninjutsu in the whole world. He is undoubtedly one of the strongest martial artist in Japan even without his other abilities.
- Well, I guess this is enough.
Yet they consider him defected good when they have to rely on him to suck fortune. Maybe they are just trying to reassure themselves that they are still superior than him just like how many smart people still have to work for the rich like slaves because the rich are powerful and blessed with wealth and fortune ever since they are born. What they don't realize is that Tatsuya can kill them all, it's just a matter of time... and unlike reality, he should be able to do it in that world when he holds such god-like power.
Any trope for this type of people? Those who think with their genitals instead of brain?