I grew up in public school, not a monastary, and have had friends of different belief and non-belief outlooks. If one wanted to persuade another to their view, I hope it was friendly and they'sd still be friends later, whatever the other decided.
If it goes beyond differences that are harmless by general ethics, if the leader is shown evidentially to be cooking up a prophet routine and anyone is hurt or killed, the jet flies into the building, a kid is shot on the Palestine border, someone throws away their nitroglycerin or insulin after Popoff told them to while wearig a radio transmitter in his ear and pretending he was getting exclusive divine guidance (near the bottom of p.1a), and an evidential expose shows it to be so, a secular dislike of lying that causes harm should be common ground.
The JWs leaders current stance is that they're not prophets (p.1 of my article) but just exclusively good at a conservative interpretation of the Bible, although playing prophet can be shown with "Noah wore argyle"-type rules and requiring agreement for salvation beyond prediction attempts (which they also require agreement to for salvation--they don't give them as pure speculation), so it's a "have your cake and eat it, too" stance. My focus hasn't been to take one of the common belief choices and attack anyone who believes differently in a cranky intolerant way. But there are common secular ethical grounds for seeing that the JWs leaders play prophet, to be critical if there are signs of deception and not signs of God for it, and especially if anyone is hurt or killed. The JWs leaders claim to be the only 12 or so that can make the rules out of a literal 144,000 of all Christian history, and they use deceptive methods when meaning to establish their distictions, and harm and fatalities have resulted (exclusive rules on the medical use of blood, pp.12-42, results in Germany and Malawi, p.6, and divisions between people with unusually strict disfellowshipping rules, p.3). There's merit in spreading a warning about it, as about Popoff, without needing to appeal to a specific religious or non-religious choice.