I liked the show because it showed three idealistic young cops and a time when idealism was at a premium. The Rookies debuted while Richard Nixon was running for re-election and we got treated nationally to all the stories about Watergate and the aftermath during the run of this show.
In that vein it was also nice to see a moral authority like Lieutenant Eddie Ryker who took The Rookies under his wing and taught them to be good cops. As a police officer Ryker was one of the best ever shown on television and it gave Gerald S. O'Loughlin his career role. He was and remains one of my favorite television police officers.
The women and the gay men certainly had a lot of nice beefcake to look at with the three Rookies. Michael Ontkean left the series midway to pursue a movie career and he's best remembered for Making Love to Harry Hamlin and Kate Jackson in Making Love and for that never to be forgotten strip tease on ice in Slap Shot. He was replace by Bruce Fairbairn for the rest of the show's run.
Speaking of Kate Jackson, she was the only regular female in the series and she played Sam Melville's wife. She was also a nurse in the emergency ward at the Santa Clara Hospital. Kate's got incredible skill or luck if you prefer in picking television series. The Rookies was her second series, she was in Dark Shadows, after The Rookies came Charlie's Angels and The Scarecrow and Mrs. King. That's one pretty substantial record and most would envy her for just one successful TV series. Kate as a nurse allowed her to get into the action in a few shows, she was not just home waiting dinner for Sam Melville. They were like a lot of young marrieds then and now, struggling to maintain a two income household and both with stressful occupations.
The Rookies were not supercops, they were young and inexperienced and made mistakes out there. Those mistakes became the basis of many a story line. But under Gerald S. O'Loughlin's wise tutelage they weren't Rookies when the series ended its run.