The answer IMO is yes. While most people don't really mind what the attenuation gets to (as long as it's not too under attenuated (attenuation is the percentage of sugars converted to alcohol)). Certain beer styles are not supposed to be entirely dry (in the fermentation sense dry means well attenuated). It's all about what you want and what you are going for.
You can also get some brettanomyces in the beer by accident which is a yeast that goes well beyond the normal attenuation of the typical beer yeast (Saccharomyces) and brettanomyces produces acid which adds sourness to your beer (which tastes amazing in a lot of styles and is done on purpose more and more).
I do not necessarily disagree with the content of the other answers here, but it goes without saying, if you mean for it to go from gravity readings of 1.070 to 1.018 but it goes down to 1.010. You aren't doing what you mean to. Most yeasts will only have certain tolerances so they under normal circumstances will only attenuate to their normal limits (normally around 75%ish).