It's perception,
Trad cleaning has been around for 100 plus years or so, WFP around 15 and in comparison hardly known about by joe public.
If a trad guy does a bad job, then you get some one else, if a WFP guy screws up, the system is blamed and leads to a mistrust of water fed pole NOT the crappy operator.
Also, when WFP goes t!ts up it really is awful and really looks bad, trad less so, the odd corner missed, a smear here, a mark there goes unnoticed.
Then you have the established almost Luddite brigade making wild claims that WFP ruins everything from glass, frames, wood and house render, not that WFP people don't counter this with claims against trad cleaners!
Then the customer really does like to think us windies work for peanuts, only earning pennies per hour, slaving away off ladders, and take hours to clean a house, not 20 minutes to earn that same £30 - what they fail to see is water fed pole eliminates wasted time moving ladders, climbing up/down etc.. WFP on the actual glass/frame is not much different.
Finally you get good and bad in both variants of cleaning
Darran