No, I'm not suggesting a possibility; I'm stating a fact based on firsthand observation and experimentation.
Here are a few easy examples:
- When you rescue a particular NPC, Diamond City Security are supposed to remark on the rescue, but the condition on that piece of dialogue checks the stage of a NULL quest, so you'll never experience that dialogue.
- When you steal from anyone in Diamond City, Diamond City Security are supposed to remark on your past theft, but the condition on that piece of dialogue checks the amount of nonviolent crime gold you've incurred with a NULL faction.
- When you encounter a shopkeeper NPC for the first time, that NPC has a line that will never been spoken because the conditions check a nonexistent stage on a NULL quest.
There are more, and more complex, issues that either require more investigation or access to Bethesda's quest design documents. Some quests are simply broken.
There is a lot of content that you'll never experience until these bugs are fixed.