Game mechanics needs purpos.
There is no need for airplanes, no need for rovers, no real need for ore to move from A to B besides missions.
Game needs some mechanics which makes sense for some of gameplay, if you can do everything with rocket, people are not interested doing it with other way than easiest.
- There is no any benefit moving ore from surface to orbit or other planets.
- I don't see any purpose for rovers after done two or couple scans with them per planet/moon.
- Why airplanes exists on game? Where do we need them? Give them purpose.