But I can understand your point. Timo could you please list some (let's say 3-4) examples where you think they ought to have mentioned/used the yacht?
Tangental, but related: there's a blanket category of evidence against Voyager's aeroshuttle in the case of the Delta Flyer; this is a craft built from scratch to accomplish what the aeroshuttle should have been designed to do from the get go; indeed, the mission into that gas giant is the ONLY kind of mission you would ever need an aeroshuttle for, and if it was so ill-suited to the task they could have easily modified and enhanced it for that task instead of building a whole new ship from scratch. Conversely, if the shuttle was so badly damaged that they couldn't even use it (nothing on the USS Voyager was ever THAT badly damaged) they could have simply ejected and scrapped it and put the Delta Flyer into that saucer slot.
Two series' in a row where every single time a "captain's yacht" or similar craft ought to be used, they pick something else instead.
I was under the impression that they build the Delta Flyer withe idea in mind that this shuttle should withstand a lot of beating, more than a typical shuttle and by extension the Aerowing could take.
And the real-world reason never seems to be "it would be expensive", as something even more expensive is done in its stead.
From what little we learn in the TNG Tech Manual, the Yacht would have been done using the standard cabin set. The same wall curvature is there, the same window shapes, the same dimensions. Picard's table would just have been replaced by a helm console of some sort, apparently.
Might have looked silly. Might have been really cool if the miniature work were good. And if the thing was a success in TNG, it could have been done in more splendor with CGI and virtual sets in the TNG movies. But of course nothing ever came of it.
At least we have Probert's cool artwork of that which never was (incidentally, with what looks like phaser strips and recessed warp engines!).
With the advent of Remastered TNG, we could very well see a CGI model of it in the near future. I wouldn't bet on it, but you never know.