Landing a spaceplane and landing a Cessna are very different things. In a Cessna, you can do a touch and go. Not so much in a spaceplane, and especially not with KSP's aerodynamics. It's more about the size of the planes you're trying to land than the world they're landing on. Let's look at some ratios. 15,000 ft / Earth's radius = 7.2E-4. 2500 m / Kerbin's radius = 0.004. Larger by a factor of about 5. This indicates that the KSC runway is plenty long enough. The space shuttle is about 37m long. This is the same size as any spaceplane you'll launch from KSC (to a decent approximation). Landing speeds are comparable. So we're landing spacecraft of the same size and speed on a much shorter runway. Yes, if you touch down you'll probably stop because of the outrageous brakes, but most of us aren't good enough at the whole piloting thing to bring an unpowered craft from orbit onto a runway that seems only marginally longer than your shoelace with enough room to stop. Practice makes perfect, and I'm well aware that KSP's learning curve is nearly vertical. And no, I don't build rockets with wings.
