The Good, The Bad, and the Badass - S3-E8
Continuity mistake: In the beginning of the episode when Daniel and Johnny try to pick up Robby from juvie, the background shows that the weather changes in an instant. When they're arguing, it's raining. When Robby refuses their help, it's sunny.
The Good, The Bad, and the Badass - S3-E8
Continuity mistake: When Sam and Miguel are "fight flirting", Robby has his right arm around Sam and his left hand is touching her. In the next shot, his hand is no longer touching her.
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