King Cobra - S3-E6
Continuity mistake: When Miguel realises Johnny liked all Ali's photos, he looks embarrassed and shakes his head to the right, with his mouth open. In the next frame he looks significantly different, with his mouth shut. (00:09:23)
Answer: Just like in the original film, some guys want that brutality. Johnny in part opens the dojo because of his past rivalry with Daniel and to train a kid that's being bullied. But also, other kids that are being bullied want to join in order to learn to fight back. Johnny is also teaching the Cobra Kai creed (Strike First. Strike hard. No Mercy.") so that's why he opens his dojo with that name and the old Cobra Kai dojo's past reputation is exactly what he wants to elicit.
Bishop73