Dimension Modeling for Big Data

HI,
I am new to Big data and getting in the process of big data. Whenever I talk about dimensional modeling, people say you should get into big data instead of getting into dimensional modeling with a bit of sarcasm, as if dimension modeling is not required for big data. I would like to know if dimension modeling is not required for big data? Since dimension modeling is a concept and process to define the unstructured data into a structured data, how it be a extinct one for db like big data?

You can read Ralph's take on it, http://www.kimballgroup.com/wp-content/uploads/2011/04/Evolving-Role-of-EDW-in-the-Era-of-Big-Data-Analytics.pdf