Yeah, in every game there are core flaws, but the flaws, bugs, and glitches are what give KSP that not only the educational aspect to it, but a humor factor that allow YouTube channels like Nexter's Laboratory and Danny 2462 to exist. Every game will eventually need a sequel, with ever increasing software and hardware capabilities, eventually it will be too hard to add to the game via update, making a new game allows the KSP franchise to future proof for the coming generations of Unity and content that would be a huge challenge to add to KSP 1.