£60k is quite possible, especially if you had a few people working for you.
Assuming that:
a) You had mainly commercial work
b) You worked even if it rained
c) You used WFP
d) You lived in London
e) You were very good (had high prices)
The problem I see here is that a newspaper article about how well paid window cleaners are, and what a great job it is, might well make a good newspaper article. But will it do our industry any good?
Won't that encourage even more so the cowboyism that already plagues the window-cleaning industry?
I can't see many bankers or stock brokers resigning from their London jobs to windowclean on the strength of a newspaper article, but I could imagine Joe Dole thinking "here is a way I can make a few easy quid - Look! window cleaners make a fortune! Anybody can do that job"
However, maybe such an article may help to raise the status of the window cleaner, in which case it would be a good thing.
-Philip