Running a game of D&D is not working cleaning shifts at the local motel. I’m very surprised that two people now would seem expect a DM not to have fun in a game if they were being paid to do it?
Do you appreciate that you are more likely to be good at a job if you enjoy it? Or that for creative jobs this is even more important. You have to at least enjoy it in part.
Let be honest most people capable of getting a $10ph paid gig as a DM can probably get considerably more down by something else. I’m surprised that you think a paid DM would do it because they’re desperate for cash rather than they passionately enjoy delivering great D&D sessions to people.
First, let me say that I think that this is a bizarre and unnecessary distraction. This isn't particularly relevant or germane to the topic of the thread, other than to acknowledge that there is a growing number of DMs who get paid for their work. That aside ...
I disagree with pretty much every thing you have written, because I disagree with the assumptions that go into it. The reason why I disagree (and strenuously) is because this rhetoric often unknowingly devalues labor. I don't think you mean to do it, and it comes from a good spot, but it nonetheless does so.
Look at the way you start by classifying different types of work. Running a D&D game (a service) "is not working cleaning shifts at the local motel." ... and so? It's also not slinging french fries, or working in a mine, or being a mime, or working as a rock star, or driving an uber. But you know what it is?
It's work. It's something that you are doing, that you are being paid to do, because if you weren't getting paid to do it ...
you would be doing something else. And while some jobs might be more physically taxing (working in a mine, waiter at a busy restaurant) and others more mentally taxing (DMing, designing logos) and others might be ... well, just taxing (toll booth operator) you are being paid for you labor.
And to denigrate the work that people do is far too common,
especially in the creative fields. "Oh, we don't need to worry about paying that graphic designer what he wants, after all, he's just an artist and I'm sure he just loves what he is doing, and he's probably middle class and not desperate for cash."
If someone is paid for their work, then it's work. Period. I respect that. To the extent that I am being overly strenuous in stating this, it's because this is a point that I feel very strongly about. People deserve to be paid for their labor, without others saying, "Oh, don't worry, it's just 'fun' for them."