Are people actively ignoring "this dude can affect gravity" when they look at his class, do they not know that if the planet was bigger they would be crushed by the higher gravity, why do people ignore the gravity part and fixate on the magic user part?
At this point I'm convinced that the MC is Issac Newton and just hasn't told anyone how gravity works, so they don't think it's anything special that could kill them just by messing with their blood flow and stopping their brains from getting oxygen