Question: Why did they fire Jenilee Harrison?
Answer: The official reason was producers felt Harrison was "too inexperienced and unseasoned" an actress (translated Harrison was probably too immature). After Harrison's first season as Cindy Snow, actress Priscilla Barnes joined the cast as Terri Alden, Jack and Janet's new roommate. Terri was a stronger, more complex character than ditzy, naive Cindy. Harrison's role diminished and Cindy was now living on her college campus. After a handful of episodes, Cindy was written out without explanation.
Answer: The producers felt that she was too "inexperienced and unseasoned" for her role on the show. Harrison admitted that she "had a lot of naivety."
Well, how else do you get experience in acting? By being on a show, in a movie, or in a play. She was fun and seemed rather sweet.
Rob245
True, but the producers apparently felt an older, more experienced actress would better play off the other characters. Shows also monitor how well viewers react to characters. Of course, there are serious reasons why actors are let go such as drug/alcohol abuse, mental health issues, legal problems, public controversies, etc, that become a liability to the show, though it's often downplayed or covered up. Charlie Sheen and Roseanne Barr are high-profile examples. If there was some other issue with Harrison, a cover story could have been issued to protect her reputation. That doesn't mean there were any, just a possibility.
raywest ★
In addition to what Ray West wrote, I want to add that many actors start out as children and young teenagers. So she could have been inexperienced compared to someone else of the same age. IMDb only lists three TV episodes that she acted in before "Three's Company."