Obvisouly, this wasn't the only reason why. The very laws and will of the world would press down on foreigners as after analysis, if the world will deemed them as safe for the inhabitants, they'd be allowed to naturally move albeit with more struggle than natives though it'd be negligible.
After a certain level, such restrictions became meaningless to cultivators as they could control space and its layers better than any world could or in some cases, which was Orion's, they'd be able to entirely adapt and subconsciously take control of those layers thanks to their bloodlines.
If Orion tried, he could most likely take full control of any world's spatial layers thanks to his True Emptiness bloodline, even in its current unawakened.
Regardless, the point was that normally, the spatial layers were harmless, especially in man made dimensions were there was no point in supressing or harming anyone.
