Clear Prop,
FYI I had little more than 150 hrs myself when I took and passed the JAA FI(R) course.
To be exact I seem to remember it was just over 200 hrs of which 150 had to be PIC.
I think you're living with the mistaken idea that people are just handed a FI rating once they achieve the required hours, not so.
First there's the exams, then there's the course and subsequent skills test (oral and practical) and even then you are only granted a restricted rating.
Just because someone has a thousand hours in their logbook doesn't instantly make them an enlightened aviator or good instructor material. Similarly someone with only 150 hrs might make an excellent tutor and this is where the vetting procedure of the course and skills test come in.
I agree that the average punter would be a bit wary if he knew his instructor had less than 200 hrs to his name but everyone's got to start somewhere.
Recently I have passed my JAA CPL and I tell you what, having done the instructors course first was a Godsend.