WDYT about heroes?

By hero I mean the developer that put in a crazy amount of effort to meet a deadline. Or make an otherwise doomed feature land. Or respond to an incident. One way or another, a hero saves the day.

I always go back and forth on this, but my question is: "are software heroes a good or bad thing?" Should we be thankful for these people, or should we be sorry when they are perpetually needed? Both?

I've seen many times where heroes are praised when they bail out poor planning. When that happens, the poor planners (typically some form of management) are reinforced in their behavior and not encouraged to correct it.

Is this a cycle others have seen? Does your company have heroes and are they a symptom or a solution? Have a perspective on the topic?