Of course some bike are smoother than others, but the FZ6 while far from the smoothest, when in proper mechanical shape isn't THAT bad. It DOES NOT need any "throttle tamer" or any other BS, otherwise the forums would be overflowing with topics like this one. I remember doing a ride on a Harley some years ago- that POS was so choppy that at slow speeds it felt like it had square wheels. Accelerating at low speeds without slipping the clutch felt like the bike wanted to throw you off.
However, after a while one should be able to adapt to almost anything. If after a few months one still can't smoothly accelerate a properly working FZ6 with no mechanical issues, maybe they should make an honest skill assessment and think about what would be needed for self improvement, rather than what to change on the bike. Even on the aforementioned Harley most people got used and rode smoothly. Surely a new bike with ride by wire set on rain or standard mode will give an huge perceived improvement but that is just technology masking bad habits.
And it's likely not only the throttle, a choppy right hand will 99% also chop the brake and the steering. I know it's hard on the ego to admit not being Rossi, but this is just an anonymous internet forum where nobody has anything to gain or lose. Heck, I can be the first one to admit that my skills are far from ideal (barely above "sucks"), if it makes anyone feel better. But in the end, it's your skin on the line, either you decide to band-aid poor technique or to actually improve it.