These are two separate arguments (i.e., #1 use of 3pp and #2 adoption of official content), but these are not equivalent or "symmetric" positions. This is comparing apples to oranges.
Perfectly symmetric. In either case you either settle for a game that doesn't perfectly suit your preferences, or you jump through a few hoops to make it so. If you don't understand something as simple as that, I'll have to take a pass at explaining it further.
How are you not embarrassed by making this sort of half-baked argument? This is yet another false equivalence. Blades in the Dark is a particular TTRPG with a particular catered experience and aesthetic. It's not trying to be a different type of game. We are only talking about the sort of game within D&D, particularly as it relates to 5e's ability to support the inclusion of past popular character types and stories of prior editions.
How are you not embarrassed at impugning my motives and character upthread?
But perhaps I am as blind to the hollowness of my own arguments as you are to yours.
It does occur to me, to give you a hefty slice of benefit of the doubt, that we just see the game differently.
I didn't play D&D for many years, and skipped 3e and 4e. It seems to have gone gonzo high-fantasy in the interim, with a huge explosion in character options, and it It became the "kitchen sink" game, discussed elsewhere, that I really don't like. The more concepts it includes under one big tent the less I like it. There's already a TON of official content that I really don't like, and, yes, it lessens my experience in practice. To the extent possible I hope they stop adding more household appliances to the mix.
I have a strong preference for games which are narrowly focused, both in terms of genre and character options. I won't bother going into (and thus starting an argument about) the reasons why, but that's my preference. I've played a wide array of games, with a huge range in character options, and I tend to enjoy the ones that have fewer character options that reinforce a specific flavor and setting.
Perhaps you see the kitchen-sink approach as intrinsic to the game, even the defining characteristic of D&D. Perhaps you can't see any downside to making it broader and more generic. Perhaps if somebody showed up at the table with a Jedi knight, complete with (mechanically balanced) light saber and pet droid, warped in through some kind of temporal rift, your reaction would be to think that's just freakin' awesome. (Spoiler alert: that would not be my reaction.).
Is that accurate? If so, it might explain why you are unable to comprehend my position.
And this strikes me as your attempt to weasel out of the issue of your attempt to gatekeep.
This suggests you have no idea what the term 'gatekeeping' refers to, and/or you assume greatly exaggerated powers on my part to influence WotC.