Which is more or less what I'm advocating: enjoy your pie/cake/whatever, and let's not whine about how this pie isn't real pie because it uses 77% cocoa chocolate instead of 70%.
But the DM doesn't like Boston Cream Pie so doesn't allow it in his game.
Same concept different thread. People have a personal taste. That is their subjective view.
Subjective: facts from the subject
Objective: facts about the object
Since the object remains the same the facts about it will remain the same, and as the subject viewing it changes, the fact form that subject will vary.
Bob doesn't se it as a pie, because pies have a top and bottom crust and this thing doesn't have a top crust, but is only a bottom crust.
The thing however is still called a pie.
Who is right, Bob of the one naming it? Bob is of course. He has to accept the name. The one naming it also is right, because of the failure for common ground and any kind of setup that forces things to be named correctly. Some sort of naming convention.
So long as there is an absence of a set of rules for naming things, and its creator can name anything what it wants from the bakery to Julliard. Someone so inclined can put boiled cabbage in it and still call it a Boston Cream Pie, since there is not a list of what can and cannot be added until it no longer becomes what the name applies to.
Both will always be right so long as anyone can name anything what they want and stick D&D on the cover of any book they have legal rights to do so with, and Bob will always be right to think it is not D&D if he does not accept the name as being what defines the thing.
The DM, the Devil, and Bob, can each like what they want, and not like what they want without needing anyone else's permission or approval such as if personal taste, be it something to allow or not in a game based on those likes and dislikes, or accepting Boston Cream as a type of pie.
I could easily say one is narrow-minded for accepting something to be D&D just because it has the name D&D on the cover, because how many people sit down and have a game with just the Dungeons and Dragons for Dummies?
The definition being change by putting the name on something that diverges further and further away form the root that held the name brings us also to the "dilution" thread. How wide can a chair be before it becomes a couch?
On that note I will leave this argument for everyone to contemplate this rectangle: