Why is the "on key pressed" condition not available in sub-events?

This seems like a strange omission, and it has gotten in the way multiple times during my current project. I must assume there's some reason for it, though I don't know what it could be.

It depends on the event. Generally you can’t have a trigger as a sub event of a trigger. You can have a trigger of normal filtering events. But it looks backwards, and actually it works as if the trigger came first and then the filter.

Anyways it makes sense to have the triggers first and other stuff under it. Guess it depends on what event you’re wanting to put the key trigger under.