Simple, it does this because you told it to. 'at' in the way you used it means "execute the following command while located at the following location". Note: not the entity needs to be located there, but the command is going to be executed from there.
What you're looking for is the 'as' option, like this:
/execute as @p[x=-160,z=68,distance=..1] run say m000
Example:

Here I asked Aya to stand on (/near) the block with the lime wool. As you can tell that was located around -160,56,60 (note that I didn't take the 'y' into account in my example). As such Aya will say 'm000' without her doing anything, that's all because of the command I used.
Hope this can help.