Personally, it seems to me like you are missing @EzekielRaiden 's point as well.
Because a person cannot discuss what is fun until they know what it is that may or may not be fun.
I mean when someone says the end goal of D&D is to make it fun... then I could just say "Okay, put a roller coaster in it." Roller coasters are fun. If all that matters is fun, then a D&D that has a roller coaster in it satisfies the request.
But of course that is a ridiculous statement to make even though it is true. Because what we are actually talking about are the rules of the Dungeons & Dragons game. What we are discussing are whether the rules-- the it-- are or are not fun. Which means the actual goal isn't "fun" in of itself, it is having "game rules that ARE fun". Step One: Make a game rule. Step Two: Have that game rule be fun to play. Step Three: Profit.
The end-result you are both looking for is the same-- a fun D&D game. It's just where your focus is to be able to get there is different.
I literally just discussed this. The whole "unexamined life is not worth living?"
As I wrote, the reason you don't understand the conversation is because you don't understand the fundamental disagreement. At a certain point, I respect that people have different ideas as to how to get to "fun." I also respect that people may not always be able to articulate what is "fun" for them, yet still be able to have said fun. People that repeatedly insist that fun is not a design goal have the implicit argument that a person's fun is an insufficient reason to play a game- something I wholeheartedly reject.
Finally, I do find it remarkable that you are insistent on "talking about the rules of the Dungeons & Dragons game" in a thread focused on second-order design.
Seriously, on the very first page I wrote this in response to @Pedantic ....
Yeah. no. I know that we have a few different theory conversations that go on here ... but the vast majority of conversations about any given RPG concern rules, and how to make them better.
Seriously. Look at 99% of conversations about D&D. They will be discussing the rules of the game. They will be discussing how the rules work (or don't work) together. They will be proposing rules modifications. They will be looking at the UA rules and parsing the language with a fine-toothed comb to look at possible issues. People will be arguing, ad infinitum, about how rules should be interpreted - RAW, RAI. Heck, I've probably seen the canons of statutory construction used more for examining rules in D&D than in your typical Supreme Court opinion.
So I absolutely, 100% can't agree with this! "Bad design" (bad rules, for example) not only goes examined, it is examined constantly, over and over and over again. But if people want to discuss .... oh .... FKR .... or talking about something else ... what happens?
Why can't you talk about rules? Do you know what never gets attention in D&D? THE RULES!
If you want to "push design forward," then please (PLEASE!) start a thread where you discuss your thoughts about good rules and bad rules. As I have stated (now, repeatedly, in multiple threads), that's not something I find particularly interesting in terms of this particular issue.
In other words, in a post focused on second-order design (quite literally, the "fun" people are having at the table, using a quote that featured "playability and enjoyability") we have people demanding that we actually look at, yes, the first-order rules. Because we never discuss that, right?