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Given the cherry picking of apparently Sigma negative comments from Roger's review, I think it's appropriate to quote his full conclusion here:
"I really don’t have a lot to add to what has already been said. From a resolution standpoint the Sigma is nearly as good as the Zeiss Otus, and clearly better than the Canon 50mm f/1.2 L. It does this at a price point far lower than either of the others. There may (or may not) be some sample variation, but I won’t know for certain until we’ve tested a lot more copies – but even the weakest two copies of the Sigma were clearly better than any of the Canon’s.
"Of course, people buying wide aperture 50mm lenses are at least as interested in bokeh, autofocus accuracy, color rendition, and a number of other traits as they are in resolution. More and more images are being posted every day to let you assess that before making a decision. But assuming those things all turn out acceptable to you, it’s hard to imagine a better value at 50mm than the Sigma 50mm f/1.4 art."
Emphasis mine.
People buy lenses for many different reasons. I'd submit those who do not value corner-to-corner clarity are in the minority.