This previous answer of mine has some relevant information about Luther's powerful political protection at the Diet of Worms.

It also should be mentioned that, despite its popular image today, the Catholic Church itself did not normally carry out judicial executions of heretics. Bloodshed would be carried out by the secular authorities, thereby leaving the church's collective hands clean. The judgement against Jan Hus, for example, reads as follows:

This holy synod of Constance, seeing that God’s church has nothing more that it can do, relinquishes John Hus to the judgment of the secular authority and decrees that he is to be relinquished to the secular court. (Official English translation, available here.

Hus was burned at the stake shortly afterwards, but technically it wasn't the church doing it. I'm not sure that this technicality was any comfort to him in his final moments, but there you have it.

Hey there,

Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.

If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!