There is a way around this of course. Like showing people what the teams are working on. For example some prototype ship interiors or some more work being done on planetary surfaces such as atmospheric conditions and volcanism. Then at least folks might think; well this stuff is not due out for months and months yet but at least we're getting some insight into what is being done, the game does have a future after all, I think I'll stick with it. Give us some more info about multi-crewing and the ship launched fighters. The absence of info just leads to idle speculation.
They are already doing this - the "sneak peek" comes with every newsletter, along with other info in the text.
"But!" you reply "the sneak peeks really aren't enough - we need more."
The practical reality is that many players have no framework with which to assess half-baked dev work. If FDev releases peeks of work-in-progress, even when it is extremely promising work the natural reaction will be screeches of horror at how stupid it looks and how useless it is (because it won't
look or act anywhere near as promising as it really is) and the forums will fill with anxious voices and angry voices and betrayed voices.
Even with people "inside" the industry, this can be a problem. Many devs are hesitant to fully pull back the curtain even for
their own publisher because even for experts it is easy to misunderstand which elements are placeholder in which ways and grasp the expected interplay of expected changes, and so draw wildly bad conclusions. Showing work-in-progress has been tried countless times and it's an ongoing problem; pulling the curtain too far back generally creates more problems than it solves.
But... more importantly; why do you need to
see something to believe they're working on something? You've been told they're working on (eg) multi-crew. That's a cool idea! And they're working on making it possible! If you were told more, why wouldn't the glaring holes in what you learned simply give you
more unanswered questions (and anxieties) as a result rather than less? Why do you think you won't end up feeling betrayed and angry at FDev if you fell in love with some part of the work-in-progress then got the final release and the thing you were expecting wasn't in it? Do you think you would happily assume that the bit you liked unfortunately introduced an unresolvable technical conflict further downstream and accept that it needed to be changed? Many players are not that insightful and will rage instead. Rage and upset is the opposite of the delight and excitement that the devs are working to give to players. Rage and hate is a horrible reward for long hours of work and passion. Is it really so terrible to be in-the-know about what they're working on, but not getting to see a preview until the preview starts to resemble the thing that will actually be delivered to you?