> Those that want to get money with the free work of others, should give something back and most authors do offer commercial licenses when asked for.
Have you ever considered the fact that it's not all about money and proprietary software? This affect Open Source software as well. If I want to allow other to do as they will with my code, I won't touch a library with such a viral license because I don't want to subject myself or my users with having to even think about it. Also, have you considered...
> With licenses like BSD, the living proof is that most companies are leechers.
That's not a proof of anything... The same license you cite is a living proof that most companies and regular people will contribute even more than they have to without you having to force them to do anything.
 most, for some definition of most, because if a company of individual have neither the expertise nor the resources to contribute, then what good does restricting their use of the code achieve? (rhetorical question)