There is such a thing as too much contrast when it comes to text. When typesetting it is advisable to never use pure black for text because it simmers on the page. I normally design the base text on the page to have between 15% and 30% brightness because it makes it more pleasant to read.

There is a place for light gray text. It is all about maintaining a hierarchy of information. Some text should be hidden away and harder to read because it is less important than the copy around it.