I love Simon Cowell. He's not 'nasty', but he is honest, and far more polite than a lot of people in the music business can be - I know, I work in it!
It's like this - if you have talent, Simon will say so, and if you get to the front, he'll put his money where his mouth is and sign you to a deal. If you are pants, Simon will give you a short sharp reality check.
Remember, he is in the business of looking for people who can make him money - anyone who doesn;t do that has to go - it''s not rocket salad is it?