I can't even be sure whether you are trolling. If you'd be saying that according to you there is only a small difference in quality I could definitely accept it, as I believe that's partly a matter of taste. But if your claim that there is almost no difference at all in those two images (i.e in colors etc) is serious then that would indeed be an indication that you do have impaired vision. Take a look again and tell me if you are honestly unable to tell that the VLC image is considerably darker, this should be something anyone could easily tell.I literally see almost no difference between the two screen shots.
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There is a small difference yes, but absolutely nothing worth caring about, let alone making a big deal out of.
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Now I see why people have problems with VLC - they are the equivalents of "audiophiles" for video
Regarding the quality difference in this particular image it becomes most apparent when you look at the darker black parts of the guy's shirt. You can easily see the VLC screenshot showing a lot of boxes, something which becomes more or less annoying depending on what is displayed (as DarkStriker pointed out earlier, one thing that low quality stands out a lot for is clear skies, which low quality can make look really bad).
On a smaller note, you shouldn't make any decision on whether VLC vs other media players is a "videophile"-only issue you should have a look at more screenshots with varied content. This particular screenshot can at most be used as an indication of there being or not being a huge difference, not a definitive answer. Besides, perceived lower quality is just one of several reasons people argue against the use of VLC.