I'm not so sure. Planets are very big things, and even with canyons and mountains all over one there'd be plenty of traversable terrain.It only takes one look at how human models look and behave on the sloped/uneven terrain to understand why planets were "flattened" to make it more "walkable". It's a horrible excuse and whoever came up with that idea should have chosen a different career path. Instead of detailing the animation and collision they went with the easiest and most damaging workaround.
This tile issue might even be a result of that as well as if you have pre-build areas it is much easier to make sure they are more "walk friendly".
It's hard to say what's going on for some things, but the fact of its general shoddy state suggests a lot of them are also broken or unfished as well. I really hope though they realise how bad repeating tiles like these are no small matter in a game like Elite, one that touts procederul generation as one of its main selling points. You just can't have features that can be as big as 100s of miles wide repeat on a planet.