I think an important qualifying aspect to this which people leave out is the notion that yeah, many men might be able to make a sexist joke or an objectifying comment and laugh off without feeling the need to go and rape someone, but some other fellas have a far lower threshold. So when we say all men need to police each other's behaviour, it's not because we think all men might be closet rapists - it's because it's the only reliable way to weed out or shut down the ones that are.
And for the men who feel put out about that - yeah it sucks that you have to be policed in this way, but surely it's better to have it set up like this than another woman is brutalised at the altar of "lad culture".
Men need/have to stop taking this as some kind of attack on them as men, and see it as a collective exercise in protecting women