If you have a properly calibrated system, such that display gamma is 2.2 (photographic work standard and standard for Internet sRGB color space), everything should look correct at gamma adjust of 1.0.
Yes, one can brighten things up with a gamma adjust of more than 1.0, but the higher the gamma adjust, the more the images will look washed out.
If this version of AH looks fine to a person then I think that person probably has either (1) a gamma adjust set higher than 1.0 (which means images are to some extent washed out compared to what they could be) or (2) has an LCD or other display that does not have a native display gamma of the standard 2.2.