[dawidw]

I don't understand why comments like above get minuses.

If you don't agree with the idea, just put that in comment. But giving minuses because someone has different thoughts.

I understand minuses when somebody is just talking things completely not true like that there never was World War II or X-Rays are safe for you.

Future is by definition not deterministic so everybody may have own imagination. And by giving minuses you're discouraging the people with sharing their thoughts with you.

At least explain you're giving minus.