As a JW, I was a window cleaner, there can be nothing wrong in principle doing an honest job as a cleaner.
Any condemnation that arose was when the JW organisation a year or two back tried to make out that its members were "ordinary people like doctors and lawyers". They are indeed ordinary but not as a rule in the professions. Of course one or two are but the vast majority of JWs are curbed by their cult-driven avoidance of higher education and often have to do more menial work.
This is a key to understanding Watchtower culture; higher education would mean exposing the individual to a use of critical analysis which would result in them awakening to their preposterous claims and methods. So parents heroically deprive their kids of worldly success by limiting their schooling.
Second, people on the lowest rung of the social ladder are dependents. In the case of JWs they depend on the JWorg for all advice, information and instruction on everything. This is how the cult leadership prefers it and to cap it all, there are measures in place to prevent members leaving by the use of emotional blackmail by family and social shunning.
Great religion hey?