I also think that there are a few % worth helping and I prefere to help them even though one now and then (or most often actually) run into those who one shouldn't help.

But then... It's also once responsibility to not give away the big plan. One should never give out once keywords and once hot niches. Better in that case (and probably help once friends more) to show them how they should find their own hot niches and monetize form them. In that way they stay out of once own business and vice versa.