"These kind of people" might come across as wrong to a few, which is completely fair and justified. But as you said - "getting them back to Earth" is a wrong idea. That implies that current situation is completely fine and these people are eccentrics, which is most definitely not correct. Rather than silencing a few who speak their minds and getting things back to (ab)normal; we need to find our own ideas on how things can be fixed, if not by the ideology proposed by such people.
We need to collectively work towards a solution than silencing a few.
“The fact that we are here today to debate raising America’s debt limit is a sign of leadership failure. It is a sign that the U.S. government can’t pay its own bills. ... I therefore intend to oppose the effort to increase America’s debt limit.” — Then-Sen. Barack Obama, floor speech in the Senate, March 16, 2006
We need to collectively work towards a solution than silencing a few.