The muslims were pushing against the boarders of Christian Europe, and Spain had fallen. Shortly after the trials and following execution of Jan Huus came the fall of the Byzantine empire at the hands of the Ottoman’s. It’s safe to say, and fair to assume that the church saw herself as persecuted and vulnerable at the time, with good cause. At the same time there we have the black plague running through Europe only 60-70 years prior to the council of Constanz (1414-18). We had had no less than three popes claiming to be the head of the universal Catholic Church at the same time. At the time of the council we saw two popes fighting for power, a dispute which ended at the council. So, the moslems at the one hand, and then the internal tendencies towards fragmentation and schism at the other hand.
There was some genuin anxiety in large part of the church. Would the church fall? That would be unthinkable, unless it’s really the endtimes.
I think it’s very unfair to ignore the historical context the church found herself in at the time of Jan Huus trial. He decided to take on the churchs authority at a very, very awkward moment. That was his risk to take and, off course, he shouldn’t have been put down over it. No one ever should be when they challenge thought patterns and ideas, but the time he chose, and the time he lived in left very little room for negotiations with schismatics coming from within the church.
When standing in front of an external enemy it’s vital to remain unified within. You can see this very same logic being applied in modern warfare. If a soldier tries to challenge the strategy of the officers in command at the battlefield, they could easily be put down if needed. It’s kind of like “for the benefit of a greater cause” kind of thinking.