I think the rotary extractor became popular because it preglide days, pushing a heavy, stainless steel unglided wand wore operators out more than the use of a rotary extractor, especially on level loop carpet on large commercial jobs.
Even though the rotary extractor cleaned better, the main reason a lot of cleaners bought them was this math:
Assuming a cleaner could "wand" 1000 square foot in an hour, that didn't mean he could clean 10,000 square feet in 10 hours. The fatigue factor broke that rate down quickly.
If he could do 1000 square feet an hour with a rotary extractor, he could keep that pace more consistently over time.
(I don't want to argue the 1000 square feet an hour number....its just a number for easy math)
That, in my view, was why so many rotary jet extractors were sold in the 90s and early part of this century.
Had
glides existed then, and had CRBs not just been in the hands of Racine Industries and Whittaker, I'm not sure we'd have seen the high sales of that style of machine.
So that's a long way of saying I think that glides helped to kill off the rotary jet extractor.....I seem to remember
Vortex and
Aerotech guys often used rotary jet extractors because they couldn't push an unglided wand with those beasts...that you would have to help me with though Mike.