Maybe it is, maybe it isn't.
If some window cleaners continue bragging about how much they can earn in such little time, than all I can say is make the most of it while it lasts because all they are doing is drawing attention to this occupation from other trades.
Before you know it every Tom, Dick & Harry will be jumping on this so called Bandwagon flooding the market causing a very healthy competition for us all.
The only winners in the long term will be the customers because they will be able to shop around for value. Customers aren't stupid and they're not all loyal!
Beware of the future!