SQUARESKULL hadn't known about the effect of her bloodline on SLEEP DEPRIVED DEMON in the past few years of being his student. It wasn't until when he mentioned it in the meeting that she had a spat with Soverick. They had casually mentioned her motive and he had honestly been terrified about the powers of such a dangerous bloodline.
He asked them why they even allowed someone like that to exist in the battle academy where they were supposed to improve the potential of the trainees. They informed him that she wasn't dangerous until she reaches the mana entity stage. Which made him ask why they allowed such an insidious bloodline to exist at all.
What they said was that there are a lot of dangers in life. If they start eliminating them all, then they will be spending a lot of manpower to prevent their offspring from growing. Those threats and dangers are meant to sharpen them and make them stronger.