Why did Gilmore Girls end their series?!

Why did Gilmore Girls end their series?

Here is an exact quote from the May 14-20 2007 TV Guide magazine that I bought that week, "Gilmore Girls Gone For Good, Say goodbye to Stars Hollow, Gilmore Girls ends it's seven year run on May 15. After lengthy negotiations to sign stars Lauren Graham and Alexis Bledel to new contracts, the CW decided to walk away from the series. According to a CW insider, the network's execs are so confident in their 2007-08 schedule development that they no longer felt the urgent need to bring 'Girls back. Luckily, the show's final episode was meant to serve as either a season or series finale, wrapping up the various story lines. -SB"

When I read that I was like wow it really is over, I had read the network announcement (pasted below for you)

"May 3, 2007 2:21pm Join statement from The CW and Warner Bros. Television regarding "Gilmore Girls" "Announcing the final season of 'Gilmore Girls' is truly a sad moment for everyone at The CW and Warner Bros. Television. This series helped define a network and created a fantastic, storybook world featuring some of television's most memorable, lovable characters. We thank Amy Sherman-Palladino, Dan Palladino, Dave Rosenthal, the amazing cast led by Lauren Graham and Alexis Bledel as well as the producers, writers and crew for giving us this delightful gem for the past seven years. We would also like to thank the critics and 'Gilmore' fans for their passionate support and promise to give this series the send off it deserves.

GILMORE GIRLS finale airs Tuesday May 15 on The CW at 8 p.m. ET/PT. "

and after reading that announcement the day it was released I was totally in Shock! with tears starting to fall and well I couldn't believe what I was reading!

But now after watching the Series Finale I feel that it was an okay Season Finale but not so much as a Series Finale but I will admit that it was a very depressing night on May 15th watching the Series Finale because it seemed to rushed only finding out it was the end. That's just my oppinion though.

Hopefully this long answer was useful to you!
~gilmoregirl4life1217