Every other show on television is a police or medical procedural and these productions go to lengths to consult professionals to at least give an appearance of verisimilitude; sci-fi similarly dialogues with the scientific community for inspiration and fact checking. This diligence is born of deference more than craft or curiosity, it is the elitism and power of lofty, status-quo figures that seem to compel TV writers' rooms to afford respect to certain corners of our economic hierarchy. Accuracy is a good thing, yet the elitism of the TV writers' room is quite apparent when it comes time to portray the lives of disenfranchised and poor people. Condescension and mockery seem to be the default brush wiped across Final Draft, but the writers themselves display their own laziness, bias and lack of curiosity when they fail to respect the representation of our cultures lesser classes. If they pay their grocery clerk, homeless, ditch digger, construction, housecleaner or unemployed characters much thought at all, they must assume that the real life people these crude caricatures are drawn from just aren't they type of people that would watch their show. 
This poor writing is apparent frequently, but I explored it further through an angle of plumbing. 

I have some knowledge of the trade as I am a failed plumber. The greatest challenges I faced in my pursuit of the trade were intellectual, and I found most plumbers I have known to have greater intelligence than the average holder of USC or UCLA graduate degrees in screenwriting. The frequency with which a plumbing issue is used as a plot device is interesting but utterly fascinating is the fact that I can think of zero examples where large details are not botched through the writing. These can be minor issues of trade vocabulary, but usually, the inaccuracies have as much to do with physics as they have to do with plumbing itself.

I take notes now when I run across examples, for a time I thought of writing a lengthy critical essay based on this premise. I made several trips to the Writers Guild Foundation library and read the scripts for episodes of Mad Men, Orange is the New Black and others to see where things when wrong. From scripts I have been able to get my hands on, it has always been in the script that inaccuracies and negative portrayals first began. I haven't written the essay, but I made a series of satirical videos where Roger Rooter incorporates my research into his reviews of television. 

Inserted here are a few examples of these videos. Since making these I have continued my research. The most notable example is Baskets, where an impossibly pressurized waste line created an impossible sewage disaster that was a significant story point across several episodes. Had the writer spent an hour talking to a plumber, they could have come up with two or three other ideas that would have been more accurate and visually interesting. Lack of curiosity and care for a large segment of humanity means you divorce your story from a segment of the population you want to reach and you lose the opportunity for inspiration and new ideas.