The thing is you payed for a game and they gave you the game. I think nowhere during the purchase it was said that you pay for "the right to have answers to development questions" or any such thing and so they are not obliged to give you any answers. It would show some good manners and good will on their side but let's be real, companies don't care about manners and a good will, only profits. And since you paid them for Elite, Horizons and now also Odyssey, you gave them what they wanted from you and are under no pressure to give you anything else than what you already have, even if it requires near zero effort on their side.
The only thing you can do is stop playing, and in the future not buy another expansion. If enough people do this, it might (and it is a REALLY big "maybe") lead to FDev noticing a drop in player base and consequently in their profits, which might (again "big maybe") lead to them trying to find out what's happened, perhaps through some questionaire/survey and if the survey has a question "Why have you stopped playing Elite?" you could tell them your reasons and then they might (again big maybe) start doing something if it shows that the majority of people stopped because "Devs don't address the issues community asks for".
I know how you feel, I think I felt the same but your stance would only have a chance to change something if they cared about your opinion but they don't and so you won't get any answer no matter how persistant you'll be. The sooner you accept it, the sooner you can stop wasting your time and move on to something else.