Sorry, but this is one of these "'twas ever thus" things. AE's default anchor point placement is smack-dab in the center of a layer's horizontal & vertical dimensions, and I know of know way to change that default. I don't know if there has ever been talk of changing it, either. People just accept that's the way AE works.
Incidentally, If you import a multi-layer Illustrator file, you'll notice that the same thing holds for the layers, even if you tweaked the anchor point in Illustrator.
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There are some scripts out there (some free, some paid) that offer some very handy movement of anchor points.
With one click, you can jump your anchor point to any of the edges of your layer!
Animation Composer is a free (handy) tool that comes with an anchor point movement script UI window.
Motion 2 from Mt. Mograph isn't free, but it includes a lot of other handy little workflow enhancers besides just the anchor point movement.
Well after more experience with AE I get now how the anchor work in comparison to position, but that tool looks like a real timesaver!