Although I have not attended Frontier training. It's all very similar .... very difficult. I've been through 4 yes 4 ... furloughed from one, and 2 company closures!
I've had to qualify for as little as one aircraft to eleven.
I must say so for the benefit of TV, Frontier has more drama. Also NO airline gives you a beautifully furnished house! You're lucky to get a hotel room. And if you get one expect to share it and love your roomie, no matter what or you're out!
and yes, sometimes people were asked to leave which seemed unfair to the people watching, but that's the way it is! Like the time (in the beginning) when a trainee was dismissed after being "just" 3 minutes late. That's the way it is in real life FA training! Airlines need dependable people.