the viewpoints presented here are all valid in some way.
but the way i see it is.... you dont need 2000+ hours to teach some zero hours guy to hover an r22 or to do a decent steep approach etc.
although i think instructors teaching commercial/CFI should have at least 500 hours
i remember as a brand new instructor i had to teach commercial students, and some of them flew the aircraft better than i did! not an ideal situation.