Actually they aren't, but I'll grant you the inaccuracy of the diagram on the basis that you were using it as a guide only. But you might want to firm it up a bit. Hint, Google Sketch Up...
I made it in five minutes in paint, what do you expect?
I said I'm granting you the inaccuracy of the diagram, in otherwords I'm not rejecting the validity of your argument just because the diagram isn't precise. It would make a good FAQ item however if you bothered to do a more precise version, but if you don't want to that's fine by me. No skin off my nose.
Mind you, the diagram needs more elucidation to make a good case. For example, what's the refraction index of light through the aether such that it will bend at the required degree to make the Moon look round to any person no matter where they are located? Given the postulate that the Moon is 3000 miles away, then that should be easy to calculate.
However, and this is where your drawing needs a lot of work; Unless the person viewing the Moon has eyes the same diameter as the moon, the lines from opposite edges of the moon will have to bend at different rates. This means the refractive index is variable depending on distance. Okay so that's not so hard to grasp. But the problem is that one of the lines of light from the closest edge will have to bend more than the line at the furthest edge, which means that the refractive index needed is less over greater distance. But then let's consider the person directly underneath the moon. The lines of travel of a lightbeam need to be less refracted, otherwise the moon would seem further away when directly overhead than when on the horizon (not explained by the myth that the moon is bigger on the horizon: it isn't, as proven by measuring it in photographs or with angular distance). So we have a refractive index that goes from being greater on the nearer edge than the farther edge of the moon for the person not directly under the moon, to being lesser for the person directly underneath the moon.
See in the below diagram; For the guy at AB, curved line AD has to be the same length as curved line BF (AD has to be the same length as AE), therefore curved line AD has to be bent more than BF.
Yet for the guy GH directly underneath the moon, lines GD and HF need to be much less bent than curved line AD in order to allow the moon to appear the same size for both GH and AB.
If you can come up with an explanation for this anomaly you might be closer to explaining bendy light,
though that doesn't explain the other problems with bendy light.20111016-001 by
max_wedge, on Flickr