It's really one of two things:
1) You aren't a very good trader. Then don't bother, because nothing they provide there will help you take it to the next level anyway.
2) You are a great trader. Then don't freely give your ideas to someone else. Find a way to monetize it yourself while keeping your trading proprietary.
Don't share your trading methods with anybody, ever ! Unless it's shit, then by all means share with the world.
I've always been a lone wolf type, not a team player...but I never understood these types of businesses. I can understand the business side of it...but for the trader...why share/exploit your strategy or skill if you are truly good?