Fair 'nuff, and in general I don't like using analogies, precisely because they are imprecise or break down, as mine did. My main goal was to show that just because you can, in theory, overlay an infinite number of channels, doesn't mean there won't be very real limits on performance.
At first glance, I though OAM sounded like circular polarization with different angular velocities. Now your comment makes me think there's more to it. Maybe someday I'll get back on track for a physics degree, and I'll be able to think through it properly.