All series have to end at sometime and Parenthood is no exception. This season should be the end of the series only if they can logically give the series closure. They should not leave any doors open and should make sure that any events that do happen would have a logical reason for happening.
I really enjoy the show Parenthood and I believe it has a few more seasons left in it. The writing has continued to be strong throughout the season and the actors still seem like they enjoy the work. I really love the interaction between the characters and I would like to see more of their stories explored.
Parenthood, the television series, is an excellent family dynamic drama that should continue to broadcast. Although the series season has concluded by closing several story lines, the television show has also opened up several new story arcs. Parenthood is unique among dramas on television. The series has touched many interesting topics including: cancer, divorce and Asperger's Syndrome.
I guess, I could see if maybe all the kids are grown up now, but technically their still parents. Parenthood does not stop just because people's children are grown up now. Technically the could keep the show running if they wanted to. The writers would just have to reinvent the story a little bit. Those are always the best stories.