Now those same people get to vote on courts and pronounce verdicts which
send people to prison. If their vote is accepted there, why not on this?

Yeah and many years back people were convinced that the earth was flat
and most would say (and if you didn`t the church knew what to do with you
;o) )
Did that make the people right? No!
So I don`t find the argument that strong, but saying that there are no
aliens
is a bifd steep, but if I believe that they visited us, that is another
matter.