I respectfully disagree on the harm.

By answering easy questions fast we create an environment where people become scared to try answering questions. I think it is important to give people who have only a partial understanding room to try answer the questions that they can get.

Why?

Well here is a list of reasons:

1. People get intimidated.
2. Trying to answer questions is an instructive process.
3. Corrections to answers gets at more subtle misconceptions than the initial question/answer. Therefore it gives an opportunity for discussions that take people to the next level.
4. Answering questions is a satisfying thing to do. Increasing how many get to experience that satisfaction broadens participation in the site.
5. It frees experienced people to spend time on more advanced discussions.

One thing that I like about this site is that there is a range of discussion levels. There isn't a rigid division between gurus here and novices there. Rather there is a spectrum of discussion and opinions that underscores the fact that novices can become gurus, and can become gurus in less time than they probably expect.

I think that it hurts that when experienced people "clean up" on the easy questions. Leave them for someone who needs the practice...