Some of the best instructors I've seen have minimal hours. It all depends on the training they have received and their aptitude for flying and teaching.
That may be so, but my experience has shown that the majority of them are barely fit to fly solo let alone teach.
I look forward to the return of the EXPERIENCED PPL Instructor and more people going into teaching because they have the desire, experience and aptitude and not just because it is a route to 'free hours' for a 'better' job.