I couldn't think of anything worse for a new student
My students saved heaps of money by learning on Microsoft flight simulators before going into the real thing. More importantly, they rapidly gained confidence which some students lose after bouts of air-sickness.
At no point during their flight training did they lock exclusively on to their flight instruments at the expense of looking outside, and there was no problem with their situational awareness. In fact quite the opposite. Their familiarity with flying the simulator allowed them to relax more in the air and keep their eyes swivelling for other traffic. Most went solo in under ten hours of dual. Nowadays it seems the average time to solo at the big well established flying schools is 15-20 hours or more. In my experience it is drawing a long bow to claim that synthetic trainer instruction prior to first flight is detrimental to student normal progress.
I read somewhere that learning to drive a car is available in a car simulator and that has measurable benefits in terms of road safety. Of course if the flying school instructor is there to make money for himself and his school, then forget simulation and get cracking on the VDO asap.