How should I respond to Latin Mass Catholics drifting toward sedevacantism and doubting the Novus Ordo?

I have dealt with them for a long time; some are so fed up with the sins in the Novus Ordo church that they cannot get beyond them. All I tell them is that the worst thing you could do is overreact to the sins in the church and get yourself out of the church; that is exactly what the devil wants. Every story in the Old Testament and everything in the New Testament is against the idea of starting another church because you are disgusted. You put up with whoever God puts in place; that is the deal. God could remove a bad pope with a snap of his fingers, but he does not, because he has planned all this and wants him there. When you decide the whole thing, Vatican II, the Novus Ordo, the ordinations, must be invalid, you become the authority instead of God, and these groups essentially turn into cults, placing their own authority over the established authority and making people feel they have committed a mortal sin by attending the ordinary form. People have the right to worship where they want without being coerced by SSPX or FSSP leaders. So respect who God has placed over you and how long he keeps him there; that is part of obeying God.