What is the primary reason that some items are reverse scored in questionnaires or surveys?

Read the von Sonderen, Sanderman, and Coyne (2013) article.  Discuss the following issues related to reverse-scored items.
What is the primary reason that some items are reverse scored in questionnaires or surveys?
What are some possible disadvantages of reverse scoring items?
If the instruments you have selected for your evaluation have reverse-scored items, why is it critical to calculate those variables before analyzing the data?
References
van Sonderen, E., Sanderman, R.,