How did Kylo Ren get his ass handed to him though? By someone who was unaware they even had the force a few hours earlier.
I guess Luke skipped lightsaber training.
Someone dares to stand up to him? He is already unbalanced by constantly failing to be as evil as Darth while thinking he should be perfect.
First that betraying stormtrooper, then the crumbling of all around him and then this, this backwater girl with no training dares?
That's enough to lose.