Why do some surgeons prefer scissors to laser to labiaplasty or the other way around?

I would't use scisso: I would not use scissors fro labiaplasty. Scissors tend to crush the tissues which will need to be sutured individually. I prefer other approaches such as radiofrequency cutting devices(ellmann) , laser or the scalpel (surgucal knife).

Labiaplasty : Lasers and other instruments are simply tools for doing a procedure. Some tools work better than others for certain jobs. I use lasers for various techniques, but not for labiaplasty as i believe it causes more pain and scar tissue than simple plastic surgical methods.

Technique: Doctors can be somewhat dogmatic about technique. We use that which works best in our experience. I am not a fan of the laser in labiaplasty.

Surgeon Matters: Like all procedures performed in the plastic surgery realm, the plastic surgeon who performs the procedure, as opposed to the specific tool used to perform the procedure, matters most. In my practice, I use a scalpel to excise the redundant tissue and do not see advantages of using a laser.