You can go as douchy as you want, I won't take offensive. It can be easier to communicate that way because you don't have to spend huge chunks of time trying to figure out ways to couch stuff and it makes communication more legible.
I always feel a bit bad responding as well because you put a great deal of effort in and then I respond with a small paragraph, sometimes because we've diverged early. So be aware that I'm taking what you say seriously even if my replies are often brief.
I don't really want to defend gamist play-styles because I don't play in a gamist way. I lack the direct experience, and passion, to lay out an in-depth case. So consider this my final thesis, based on reading about and talking with people in that community.
In competitive games, including solo games like crosswords, you're testing a specific skill or variety of skills. In the case of a crossword someone has constructed a puzzle but it's not enough that it just be hard A good crossword, even at the highest level, has to reveal itself as hard and fair. Such that if you fail and someone explains why you failed, you can slap your forehead 'doh, of course.'
There are people that consider some games more pure than others. So chess is more pure than poker because it doesn't have random elements. I'm not one of those people. Good competitive games can include randomness for a variety of reasons. The important thing is that skill will eventually reveal itself because there is still skill involved. But too much randomness can destroy the ability show skill.
I don't hold to the idea that roleplay is a form of simulation and so I agree with your dismissal of the unicorn. Or it is a form of simulation but more doesn't mean better. The Star Trek holodeck is not necessarily better than an osr game because it simulates more fully.
The best analogue I can come up with when describing pure fiat based resolution is figure skating. Competitive figure skating does exist. It does show skill. It does depend on impressing the judges and part of the skill of winning is knowing how to do that. Challenge based fiatists I've spoken to have been open about that. That knowing the DM and how they work is something you can use to your advantage. Unless you're aiming for some kind of holodeck sim, this isn't necessarily a bad thing. In fact it is a good thing because part of the reward for role-playing is social and this includes esteem. You want your friend to judge you.
So in conclusion. The type of play I'm talking about is some mix of a crossword puzzle and figure skating.
Do I think that's the 'best' type of gamism? Hard to say because I don't play in that style. In a kind of value conceptual sense it appeals to me the most in it's use of the form.
As regards Narrativism you'd have to lay out your case in a bit more depth for me to respond. Given I see group consensus as the death of play but unilateral fiat as its beating heart I suspect we're on totally different pages.