Kavanaugh Can Join Thomas.

[RoadRunner79]

And the doctor may be wrong and the dishwasher may be right (despite your assumptions).

Sure. Hell, the dishwasher might be a genius with multiple Ph Ds and is down and out due to some other problem. But in the vast majority of cases, the doctor is smarter and better educated than the dishwasher.

Appealing to or attacking the person (or what they do for a living) is fallacious thinking.

Nope, there are reasonable assumptions that can be made based on a person's occupation. I get that you find it distasteful - I didn't say it because I was being nice you know - but don't kid yourself.

Some letters after someone's name or a degree, may mean that they have demonstrated a certain amount of knowledge.  But it doesn't tell you if they are wise or sometimes even if they can properly utilize that knowledge.  I've met engineers that have a PHD, and they are dumber than a box of rocks.  They don't have any common sense, or experience to apply that knowledge.   Appealing to ones occupation is just an appeal to authority, and ad hominem.   If all you are given is the education or occupation, then all you have to go on is those assumptions you mentioned.   However if the dishwasher makes a better argument for the idea at hand, then it doesn't matter what their job is.  As in most of the informal fallacies you are guilty of ignoring the argument, and appealing to something which is largly irrelevant, and doesn't tell you much of anything about the argument.