I think it's because humans can easily confuse the pull caused by gravity with a pull caused by acceleration.

It's not just humans -- the basic idea of general relativity is that (short of looking out or detecting tidal effects) it's impossible in principle to tell them apart.

We could tell the difference using the visual cues when we run or jump.

Running a lot is something quite natural for humans but not done much by Westerners. That means that the default mode of feeling pull is not well developed. Because it's unclear what you are actually feeling it's more difficult to adept to the changing meaning of the feeling.