I thought the same. But I tried. It’s not as hard as it looks, it just takes time to build the resistance.
The actual enemy is your mind, once you overcome the fear of the feeling and just step into the cold you realize that it’s just water and then you actually feel good.
The nice thing about it is that it’s like forcing yourself to meditate, because while you’re doing it you can’t think about anything else. So it really frees your mind.