My FZ6 was my 3rd bike and it was also the 3rd for my wife.
The first consideration is the size of the rider. For an FZ6 to be a beginner bike, the rider needs to be somewhat tall and strong. The height and strength needs definitely become less with experience. My wife NEVER could have had her FZ6 as her first bike.
The next consideration is maturity, and rider education. If the rider is a responsible adult, with a healthy respect for the risks involved with riding, then the FZ6 could be a decent first bike. Below 6 to 8k RPM's the bike is really docile, above that, and it becomes a bike that is NOT for new riders. The education part is simple, take, and pass, a MSF Basic Rider course before getting on the bike.
My first bike was a 1982 Suzuki GS450, that was actually a great first bike. Nice size, not super fast, but could outpace most 800cc cruisers.
Really, the FZ6 is a great 2nd bike that you will want to keep for a long time.