The burden of proof rests squarely on the shoulders of the people making the assertion. That's how science works. It's also fundamental for intelligent debate.
E.g.
"Science is sexist" - well, what evidence do you have to support your assertion?
"Trump is not only a racist, he's also a fascist" - again, show me the evidence, please.
"The USA is racist" - er, you're not stupid, you get the idea.
"Jeremy Corbyn hates Jews" - again: evidence, please.
Yeah, good thread Min- people who make assertions need to provide supporting evidence. Otherwise, they might be talking crap.
That's how science works; that's how intelligent debate works.
"That which can be asserted without evidence can be dismissed without evidence" - Christopher Hitchens.