There are many different grades of wood: #2 common, #1 common, select and clear. Some of the highest grades of wood are more than likely reserved for the higher-priced pieces of furniture. If you wanted a piece of furniture with with perfect wood, you'll pay dearly for it.
I've come to appreciate imperfections in wood - because they are natural. However, I do have clients who I know are very particular and when doing something for them out of wood, I'm quite careful in how I select the pieces that I use. For a mark that I would consider natural, they will take notice to it - so, for that reason alone, I'll just try to use perfect pieces where possible.