"this exemplifies why" is a correct and usable phrase in written English.
You can use this phrase to explain or demonstrate the reasons behind something, usually used to explain why something is the way it is. For example: "This exemplifies why it is important to stay organized in the workplace; organization leads to increased productivity and efficiency."
A film that could be made today, programming like this exemplify why the National Gallery is our favorite place to see free films in D.C. 4 30 p.m., all ages, no cover.
Last night's collection, which featured some of the most elegant dresses that will probably be seen in London this week, exemplified why the fashion know-alls have long championed her, and why, more importantly perhaps, she has been chosen to design the clothes for the opening and closing ceremonies of this summer's Olympic Games in Athens.
HAMBURG, Germany — An eight-hour production of Goethe's "Faust" may be the highbrow hit of the fall at the grand Thalia state theater here, but it is an altogether different blockbuster — the Disney musical "Tarzan" — that exemplifies why modern Hamburg has become that rare thing in the theater world: a reliable profit center for producers outside of their two biggest markets, New York and London.
TV Fanatic's Chandel Charles agreed, writing, "This installment clearly exemplifies why Season 8 is a gift to fans, and why this show has been so successful over the past number of years.
Of course, this very freedom exemplifies why unencumbered sexual pleasure presents such a problem for those who would support the sexually repressive ideologies that still prevail today.
Tell a story of some specific detail or action that exemplifies why this person is special in this world, and to you in particular.
We recently met a veteran who exemplifies why this approach must be expanded.
"The concept that insurance companies would even seek to deny children coverage exemplifies why we fought for this reform," said Representative Henry A. Waxman, Democrat of California and chairman of the Energy and Commerce Committee.
I do not regret providing such a culture shock to this place – quite the opposite – but that reaction exemplifies why the issue of homeless women's access to sanitary care is so widespread and terribly underestimated".
Iceland's tale exemplifies why central banks around the world are spraying liquidity at the financial system to keep banks in business.
