We have some jet pilots that fly high end, high dollar jets in our club. They use current gyro systems of some sort, I think they use the AS3000 Spektrum units actually, but the stabilizer feature makes these jets extremely stable and realistic, and allows for very realistic landing and maneuvering of all sorts.
As mentioned there are several gyro devices and systems available, and each has its place.I'm sure.

To say they're "totally unnecessary" is wrong though. That's a bold uneducated statement that's just ridiculous. They might not be necessary for many applications, but that's for the user to decide... and can't be determined with a "total" statement.

A stabilizer or gyro won't make a person suddenly an instant pilot either. A person still has to have the skills and knowledge of how the plane flys, and knowledge of how to set it up. I can say though, some of the best pilots flying the high end jets are smart enough and good enough that a gyro/stabilizer really enhances the incredible skills they already have... and they use these things to the fullest.