Granted, this thread is a little old, but its a subject that i have strong opinions about. I agree with OP. In fact, the one thing that spoils sandbox, for me, is the lack of roleplay. Lack of immersion. I prefer Sandbox due to it giving the ability to be creative without limits. I purchased KSP for exactly that. Thats not to say i never play in career mode. But i admit that i prefer Sandbox. When i saw the scientific instruments, for the first time, the game became so much more than the challenges of orbits, landings and all matter of other challenges. Until i tried to use them.... At which point my excitement dropped faster than a Kerbal who turned off his jetpack mid-flight. Sure i still have the other features of the game, and they keep me playing. But having science would complete sandbox, for me. I am not talking about having a tech tree. Thats for Career mode, and rightly so. But having the immersive messages, and even a total of the points i have accrued. Thats perfect. I can do science, and feel i have achieved something. It also gives me more reason to play.