Fair enough, let's put some "facts" on the table shall well?

.....
/facts
A bit thin on fact and very heavy on the opinion.

Most of your argument is based on your own idea of what should have happened and how the game doesn't deliver some very specific scenes from your own imagination (well worn film/sci-fi series tropes that you'd like to be "inside") and some well-trodden game play trends you've seen in other titles. It reads very much like the rant of what could be termed an armchair games developer. I'll certainly side with you about some features of the game being either underwhelming at first try or being limited in slightly unfathomable ways but, as well as coming to like and enjoy a lot of what others say is broken/terrible design, I wonder how else things could be done so that
all players get a shot at all aspects of the game, rather than the clever and obsessional few with too much time on their hands bagging all the thrills. And in that respect I think they've done a pretty good job.
From my own perspective I've only just engaged with any of the Thargoid story (I've been playing on and off since launch) and have certainly found that the main aspect of the Thargoids - i.e. a difficult adversary in space combat - is definitely fulfilled; they are a difficult opponent and that's even when well prepared and kept in a somewhat separate space from the rest of the game. But for most of the time I knew that they were about somewhere but had too much other stuff to be getting on with so I paid no heed. Occasionally I happened upon a damaged or repairing station and enjoyed the gameplay of that. I
liked the fact that I'd missed the actual action and was just witnessing the aftermath. It gave things a sense of scale. But I often wondered when I would end up getting intercepted in hyperspace (as in the original game) by Thargoids and so even though my CMDR hadn't any experience of them they added a layer of depth to the galaxy. That trouble brewing just out of sight. I like that about ED - there's almost too much now for any one CMDR to see and do, and that goes a long way.
I think that there will come a time in ED when Thargoids are mixed in with the rest of the game a bit more liberally but clearly, dealing with them takes a bit of preparation and time and new players would likely find it way too challenging. So, for now you've got to go looking for trouble as far as Thargoids are concerned and that does inhibit the urgency and excitement of the story around them.
But hey, I'm a crusty old veteran from '84 and I enjoy ED in large part just because it's Elite and it still exists. I went off computer games as something to get excited about or worry about sometime in the last century and a lot of games that others seem to find so excellent I find to be technically amazing and well executed half-baked dross when judged in terms of gameplay and fun, so horses for courses, I guess. And please remember that ED doesn't have to keep up or follow the trends of other games since it is
thee original 3D open-gameworld space trading combat simulator game. Seminal, ultimate, genre-defining etc are superlatives that still hold even now.
I certainly wouldn't dream of getting het up about how FDev have somehow failed the consumer.
yawn Since they clearly haven't.