Nina Dobrev and Elena have been at the heart of the show since it began, of course they'll both be missed. If Nina wanted to leave the show, there wasn't really any choice, but Elena in exchange for Bonnie isn't an even trade. Many fans would rather have seen Bonnie go, and will continue to say so.
"Saying goodbye to Nina is both bittersweet and beautiful," said Plec. "After six-plus years together, the entire cast and crew of The Vampire Diaries has reached a level of closeness that I don't think any of us ever expected. Nina is excited to spread her wings, get some rest, travel the world and also take it by storm, and we support her a thousand-fold. We will miss Nina and the four hundred characters she played, but we look forward to the insane and exciting challenge of continuing to tell stories of our Salvatore Brothers and our much-loved and gifted ensemble."
Nina Dobrev is one of the original and central characters to the very popular Vampire Diaries. She's been part of the story since the first season, starring for six seasons total. The young and dedicated viewers of this series will surely miss her in the seventh season. What new doors will open with such a loss?
Over time, actors and actresses develop relationships with each other and their viewers. The show actors and actresses and viewers will miss the actress in Nina Dobrev. Unless, there are a series of flashbacks, the actress will not be around on the set to continue in the legacy of this show.