This is one problem, in my opinion, with sedevacantists.
They take their own personal beliefs/piety/virtue/devotions and make it mandatory for everyone, sometimes even under pain of sin.
While I'm not a sede, I partially disagree with this statement. I think most pastors in tradition all differ from each other. Think of the varying degree of non-sede, independent priests as compared with SSPX- there are definitely differences between them. Now think about whats happening with the Feleyites and Williamites. There is a ready schism, or at least there are many waiting for it.
In many regards I think the society is, and perhaps will soon be 'was', one of the best groups around, sede or non-sede, for two primary reasons. One was because of the caliber of theologians who once belonged to it, though now mostly dead, and even some of them eventually broke ties with it. The second is its priestly formation; but even the formation itself had its own problems (think of, eating your own).
Sometimes what bothers me most about some of the society priests I know is that they can be superficial. A priest may walk around in impressive and expensive cassocks, with their spiritual sheath at their side, and look magnificent, yes. But if that priest engages in calumniation against other priests, and degrades people both privately and publicly, with no real motive apart from anything unholy, then whats the point? Fortunately, I've met some of the holiest men I've ever known who were priests of the society. But sadly, for each one who was good, there was one who was less than noble; one who was tyrannical and even controlling of the 'good' ones. Power-hungry, and material driven (objectively). Of course, my own priest now (non-sspx) has taught me to pray for these men, continually, by his own actions than by his words. Even for the very priests who have even acted unjustly towards and calumniated against him.
Back on the topic, yes, there are some who make it seem and believe that if you don't agree with them, it is under pain of sin. But thats why it so important to us to be learned in these times- both SSPX, non-sspx, sede and sede-friendly- all of us. I've been reading a bit about the reformation lately. I remember reading that just before it happened, there was an advent of new heresies continually sprouting up. One guy here would come up with a heretical idea, another there would do the same. I was thinking, we're very much in that same sort of state. There are indeed many heresies sprouting up amongst some in the Traditional world. In order to know what Truth is, and who to trust, we, even as laymen, must be knowledgeable as never before.
That's why I like CathInfo so much. Not only does it keep me aware of the goings on in Traddie land. But there is a wealth of spiritual knowledge to be found here from both from other members, and in the library.